Co-reporter:Jihuai Wu;Zhang Lan;Jianming Lin;Miaoliang Huang;Yunfang Huang;Leqing Fan;Genggeng Luo;Yu Lin;Yimin Xie;Yuelin Wei
Chemical Society Reviews 2017 vol. 46(Issue 19) pp:5975-6023
Publication Date(Web):2017/10/02
DOI:10.1039/C6CS00752J
Dye-sensitized solar cells (DSSCs) are regarded as prospective solar cells for the next generation of photovoltaic technologies and have become research hotspots in the PV field. The counter electrode, as a crucial component of DSSCs, collects electrons from the external circuit and catalyzes the redox reduction in the electrolyte, which has a significant influence on the photovoltaic performance, long-term stability and cost of the devices. Solar cells, dye-sensitized solar cells, as well as the structure, principle, preparation and characterization of counter electrodes are mentioned in the introduction section. The next six sections discuss the counter electrodes based on transparency and flexibility, metals and alloys, carbon materials, conductive polymers, transition metal compounds, and hybrids, respectively. The special features and performance, advantages and disadvantages, preparation, characterization, mechanisms, important events and development histories of various counter electrodes are presented. In the eighth section, the development of counter electrodes is summarized with an outlook. This article panoramically reviews the counter electrodes in DSSCs, which is of great significance for enhancing the development levels of DSSCs and other photoelectrochemical devices.
Co-reporter:Yongguang Tu;Jihuai Wu;Xin He;Panfeng Guo;Tongyue Wu;Hui Luo;Quanzhen Liu;Qihui Wu;Jianming Lin;Miaoliang Huang;Zhang Lan;Sizhong Li
Journal of Materials Chemistry A 2017 vol. 5(Issue 40) pp:21161-21168
Publication Date(Web):2017/10/17
DOI:10.1039/C7TA03890A
Further efficiency enhancement mainly relies on decreasing the interface losses between the active layers in perovskite solar cells. The design of a gradient engineered hole-transporting material is expected to tune the interface losses in perovskite solar cells. In this work, we reported gradient engineering that afforded the hole-transport material (spiro-OMeTAD) dispersed in the upper part of the perovskite layer. Photoluminescence measurements indicated an enhanced hole extraction from the perovskite–spiro-OMeTAD gradient film. And a maximum PCE of 19.16% and a steady-state efficiency of 18.01% were obtained for the small-area device. Furthermore, we assembled monolithic series-type large-area perovskite solar cells based on gradient engineering. The large-area perovskite solar cell with an active area of 1.01 cm2 obtained a PCE of 16.61%. Moreover, monolithic series-type large-area perovskite solar cells showed a Voc of 2.095 V for the binary module and a Voc of 3.104 V for the ternary module, respectively.
Co-reporter:Rui Xu, Jianming Lin, Jihuai Wu, Miaoliang Huang, Leqing Fan, Xin He, Yiting Wang, Zedong Xu
Electrochimica Acta 2017 Volume 252(Volume 252) pp:
Publication Date(Web):20 October 2017
DOI:10.1016/j.electacta.2017.08.148
•CoMoO4/Co9S8 nanorod arrays on Ni foam was synthesized by hydrothermal route.•CoMoO4/Co9S8 exhibited a superior capacitance of 9.17 F cm−2 (2059.26 F g−1).•A high energy density was equal to 42 Wh kg−1 for an asymmetric design.CoMoO4/Co9S8 nanorod arrays supported on nickel foam are successfully assembled via a facile two-step hydrothermal route. Due to the unique nanorod array structure, the CoMoO4/Co9S8, as the electrode, possesses a high capacity 1.54 mA h·cm−2 (343.21 mA h·g−1) and a large capacitance 9.17 F cm−2 (2059.26 F g−1) at a current density of 20 mA·cm−2 (4.44 A·g−1), and an excellent cycling stability (8.6% degradation after 3000 cycles). The asymmetric supercapacitor based on the CoMoO4/Co9S8 nanorod arrays as a positive electrode and porous active carbon as a negative electrode in an alkaline KOH aqueous electrolyte is fabricated. Owing to the synergetic effect between CoMoO4/Co9S8 and active carbon, CoMoO4/Co9S8//active carbon asymmetric supercapacitor exhibits an outstanding energy density of 42 Wh·kg−1 and an excellent cycling stability with 89.5% specific capacitance retained after 5000 cycles in an operating voltage of 1.6 V. The facile synthesis route and remarkable supercapacitive performance of the CoMoO4/Co9S8 nanorod arrays is promising as a positive electrode materials for high-performance asymmetric supercapacitors.Download high-res image (194KB)Download full-size image
Co-reporter:Jia Dong, Jihuai Wu, Jinbiao Jia, Leqing Fan, Jianming Lin
Journal of Colloid and Interface Science 2017 Volume 498(Volume 498) pp:
Publication Date(Web):15 July 2017
DOI:10.1016/j.jcis.2017.03.025
Nickel selenide/reduced graphene oxide (Ni0.85Se/rGO) nanosheet composite is synthesized by a facile hydrothermal process and used as counter electrode (CE) for dye-sensitized solar cells (DSSC). The Ni0.85Se/rGO film spin-coated on FTO show prominent electrocatalytic activity toward I3−/I−. The electrocatalytic ability of Ni0.85Se/rGO film is verified by photocurrent-voltage curves, cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization curves. On account of its decent electrical conductivity and superior electrocatalytic activity, the DSSC using optimal Ni0.85Se/rGO CE achieves a power conversion efficiency (PCE) of 9.75%, while the DSSC based on sputtered Pt CE only obtains a PCE of 8.15%.Download high-res image (124KB)Download full-size image
Co-reporter:Tongyue Wu, Jihuai Wu, Yongguang Tu, Xin He, Zhang Lan, Miaoliang Huang, Jianming Lin
Journal of Power Sources 2017 Volume 365(Volume 365) pp:
Publication Date(Web):15 October 2017
DOI:10.1016/j.jpowsour.2017.08.074
•Cation-anion-mixed perovskite is grown in ternary-mixed-solvent containing NMP.•Dense, large grain, pinhole-free and long charge lifetime perovskite film is made.•The device with the mixed perovskite film achieves an efficiency approaching 20%.The perovskite layer is the most crucial factor for the high performance perovskite solar cells. Based on solvent engineering, we develop a ternary-mixed-solvent method for the growth of high-quality [Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3] cation-anion-mixed perovskite films by introducing N-methyl-2-pyrrolidone (NMP) into the precursor mixed solution. By controlling rapid nucleation and retarding crystal growth via intermediate phase PbI2-NMP (Lewis acid-base adduct), a dense, large grain, pinhole-free and long charge carrier lifetime perovskite film is obtained. By optimizing the precursor solvent composition, the perovskite solar cell achieves an impressive power conversion efficiency of 19.61% under one-sun illumination. The research presented here provides a facile, low-cost and highly efficient way for the preparation of perovskite solar cells.
Co-reporter:Jinbiao Jia, Jihuai Wu, Jia Dong, Quanlin Bao, ... Songyuan Dai
Solar Energy 2017 Volume 151(Volume 151) pp:
Publication Date(Web):15 July 2017
DOI:10.1016/j.solener.2017.05.036
•CoSe2 is successfully synthesized by electrochemical deposition method.•The preparation method is facile, environmentally friendly and economic.•The DSSCs device based on CoSe2 possess a power conversion efficiency of 10.17%.•CoSe2 counter electrode has an extreme stable character.Cobalt diselenide (CoSe2) is endowed with excellent and stable photoelectrochemical properties. However, the preparations of CoSe2 usually need high pressure, high temperature, long reaction time or special devices. Here, CoSe2 counter electrodes are prepared by a facile electrochemical deposition method and controlling different deposition voltage. The influence of deposition voltage on the film quality and the performance of dye-sensitized solar cells is investigated, and the CoSe2 counter electrode with –1.1 V deposition voltage achieve a best power conversion efficiency of 10.17%, which has a 21.9% increase compared to the solar cell based on platinum counter electrode (8.35%). The impressive efficiency together with facile preparation highlights the potential for substitute for the noble metal platinum.
Co-reporter:Xin He, Jihuai Wu, Yongguang Tu, Jinbiao Jia, Jia Dong, Rui Xu, Qiyao Guo, Tongyue Wu, Zhang Lan, Jianming Lin, Yimin Xie
Journal of Power Sources 2017 Volume 365(Volume 365) pp:
Publication Date(Web):15 October 2017
DOI:10.1016/j.jpowsour.2017.08.063
•TiO2 nanoparticles with diameter of 3.6 nm are synthesized by solvothermal method.•The TiO2 is modified with acetylacetonate for high quality and low resistance ETL.•The device efficiency enhances from 17.25% to 19.21% after TiO2 ETL is modified.•Along with a significant decrease of J-V hysteresis.Electron transport layer (ETL) plays an important role in improving charge transportation, suppressing current-voltage hysteresis and enhancing photovoltaic performance of perovskite solar cells (PSCs). Here we successfully synthesize anatase titania nanoparticles (TiO2 NPs) with an average diameter about 3.6 nm by a facile and low-cost solvothermal method. Using the as-synthesized TiO2 NPs as ETL, the planar perovskite solar cells exhibit good photovoltaic performance. Encouragingly, when the TiO2 NPs are modified with titanium acetylacetonate [TiO(acac)2], a pinhole-free, dense, low charge transfer resistance and high charge extraction TiO2 ETL is formed and the power conversion efficiency of the planar perovskite solar cell is enhanced from 17.25% to 19.21%, accompanied by a significant decrease of J-V hysteresis. The facile process and significant performance improvement suggest that acetylacetonate modified TiO2 nanoparticles could be good ETL candidates for high-performance planar perovskite solar cells with low hysteresis.Photocurrent-voltage curves of the planar perovskite solar cells based on unmodified and modified TiO2 NPs ETLs under reverse and forward scan.Download high-res image (197KB)Download full-size image
Co-reporter:Sha Bao, Jihuai Wu, Xin He, Yongguang Tu, Shibo Wang, Miaoliang Huang, Zhang Lan
Electrochimica Acta 2017 Volume 251(Volume 251) pp:
Publication Date(Web):10 October 2017
DOI:10.1016/j.electacta.2017.08.083
•Large grain and mesoporous Zn2SnO4 are synthesized by a facile hydrothermal method.•Perovskite device with Zn2SnO4 electron transport layer get efficiency of 17.21%.•While the device with TiO2 electron transport layer obtain an efficiency of 14.83%.•Superior photovoltaic performance stems from the intrinsic characteristics of Zn2SnO4.Electron transport layer with higher carrier mobility and suitable band gap structure plays a significant role in determining the photovoltaic performance of perovskite solar cells (PSCs). Here, we report a synthesis of high crystalline zinc stannate (Zn2SnO4) by a facile hydrothermal method. The as-synthesized Zn2SnO4 possesses particle size of 20 nm, large surface area, mesoporous hierarchical structure, and can be used as a promising electron-transport materials to replace the conventional mesoporous TiO2 material. A perovskite solar cell with structure of FTO/blocking layer/Zn2SnO4/CH3NH3PbI3/Spiro-OMeOTAD/Au is fabricated, and the preparation condition is optimized. The champion device based on Zn2SnO4 electron transport material achieves a power conversion efficiency of 17.21%, while the device based on TiO2 electron transport material gets an efficiency of 14.83% under the same experimental conditions. The results render Zn2SnO4 an effective candidate as electron transport material for high performance perovskite solar cells and other devices.
Co-reporter:Yunfang Huang, Yuelin Wei, Jing Wang, Dan Luo, Leqing Fan, Jihuai Wu
Applied Surface Science 2017 Volume 423(Volume 423) pp:
Publication Date(Web):30 November 2017
DOI:10.1016/j.apsusc.2017.06.158
•TiO2-Bi2O3 with hierarchical morphology is achieved on FTO electrodes.•Combined hydrothermal, sol-gel hydrolysis and calcination step is followed.•Morphological evolution and heterojunction formation is critically discussed.•Composites were active for dye degradation under visible light.Three-dimensional Bi2O3/TiO2 hierarchical composites have been successfully prepared by a two-step hydrothermal method and subsequent calcination. The samples were characterized using XRD, SEM, TEM, EDS, BET and DRS. The measurement results signified that heterojunctions of various morphologies β-Bi2O3 growing on the three-dimensional hierarchical anatase TiO2 nanorods arrays on FTO glass were apparently formed. The morphology of Bi2O3 changed from three-dimension flower-like microstructures to the sphere-like nanoparticles as the Li(OH) dosage increased. The photocatalytic results showed that all samples exhibited much higher photocatalytic activities than that of pure Bi2O3 and TiO2 (P25) in photocatalytic degradation of methyl blue (MB) under visible-light irradiation. Whereas BTL4 sample exhibited the highest photoactivity with increasing the dosage of Li(OH) to 2 mmol. Furthermore, the absorption edge of the Bi2O3/TiO2 series composites displayed a broad-spectrum photoabsorption from UV to visible-light compared with the individual component. The as-synthesized Bi2O3/TiO2 composites possessed excellent photocatalytic activity and outstanding recyclability. The enhanced photocatalytic efficiency was mainly attributed to the Bi2O3/TiO2 p-n heterojunctions and hierarchical nanostructure. The recombination of photogenerated electron–hole pairs was efficiently suppressed by the Bi2O3/TiO2 p-n heterojunctions.Download high-res image (174KB)Download full-size image
Co-reporter:Jia Dong;Jihuai Wu;Jinbiao Jia;Leqing Fan;Yu Lin;Jianming Lin;Miaoliang Huang
Journal of Materials Chemistry C 2017 vol. 5(Issue 38) pp:10023-10028
Publication Date(Web):2017/10/05
DOI:10.1039/C7TC03343E
In this report, redispersable CdS nanoparticles are synthesized via a specific one-step solvothermal reaction and are employed as electron-selective materials for organometal halide perovskite solar cells. The as-synthesized CdS nanoparticles can be well re-dispersed in toluene to form a uniform and stable CdS ink. On this basis, a CdS electron-selective contact layer can be directly prepared by spin-coating CdS ink and without a further annealing process. The CdS electron-selective contact layer has high optical transmittance at visible wavelengths. Its electron extraction and transfer properties are also investigated using current density–voltage curves, incident photocurrent conversion efficiency, stabilized current density and photoluminescence spectra. The use of a CdS electron-selective contact layer in a planar perovskite solar cell equipped with a Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3 light-absorption layer results in a high power conversion efficiency of 16.5%.
Co-reporter:Yongguang Tu;Jihuai Wu;Xin He;Panfeng Guo;Tongyue Wu;Hui Luo;Quanzhen Liu;Kai Wang;Jianming Lin;Miaoliang Huang;Yunfang Huang;Zhang Lan;Sizhong Li
Journal of Materials Chemistry A 2017 vol. 5(Issue 9) pp:4376-4383
Publication Date(Web):2017/02/28
DOI:10.1039/C6TA11004E
The organic–inorganic lead halide layer is a crucial factor in determining the photovoltaic performance of perovskite solar cells. Based on solvent engineering, we developed a three-step sequential coating method to prepare a high-quality CH3NH3PbI3 layer based on solvent (isopropanol) substitution. Stonehenge-like PbI2 nanostructures with controllable morphology and crystallinity were prepared by solvent substitution instead of the conventional annealing-treatment, affording several channels for CH3NH3I to penetrate into the PbI2 film due to volume expansion, and thus enabling the complete conversion from PbI2 to perovskite. In addition, the device exhibited high reproducibility by our method and achieved a high 17.78% power conversion efficiency under one-sun illumination. Furthermore, we optimized the production craft and successfully fabricated a uniform perovskite film (10 cm × 10 cm) via solvent substitution.
Co-reporter:Quanlin Bao, Jihuai Wu, Leqing Fan, Jinhua Ge, ... Jianming Lin
Journal of Energy Chemistry 2017 Volume 26, Issue 6(Volume 26, Issue 6) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.jechem.2017.09.023
•NiSe2 nano array is grown on carbon fiber cloth by a simple electrodeposition method.•NiSe2 electrode shows a large specific capacitance of 1058.5 F g–1 at 2 A g–1.•Asymmetric NiSe2||AC has potential window of 1.6 V and power density of 800 W kg−1.•Superior performance roots in NiSe2 character, nanostructure and high conductivity.A flexible electrode of nickel diselenide/carbon fiber cloth (NiSe2/CFC) is fabricated at room temperature by a simple and efficient electrodeposition method. Owing to NiSe2 character of nanostructure and high conductivity, the as-synthesized electrodes possess perfect pseudocapacitive property with high specific capacitance and excellent rate capability. In three-electrode system, the electrode specific capacitance of the NiSe2/CFC electrode varies from 1058 F g–1 to 996.3 F g–1 at 2 A g–1 to 10 A g–1 respectively, which shows great rate capability. Moreover, the NiSe2 electrode is assembled with an active carbon (AC) electrode to form an asymmetric supercapacitor with an extended potential window of 1.6 V. The asymmetric supercapacitor possesses an excellent energy density 32.7 Wh kg–1 with a power density 800 W kg–1 at the current density of 1 A g–1. The nanosheet array on carbon fiber cloth with high flexibility, specific capacitance and rate capacitance render the NiSe2 to be regarded as the promising material for the high performance superconductor.A flexible electrode of nickel diselenide/carbon fiber cloth is fabricated by a facile and efficient electrodeposition method. The electrode demonstrates a perfect specific capacitance (1058 F g–1 at 2 A g–1) and excellent rate capability. Download high-res image (95KB)Download full-size image
Co-reporter:Xin He, Panfeng Guo, Jihuai Wu, Yongguang Tu, ... Miaoliang Huang
Solar Energy 2017 Volume 157(Volume 157) pp:
Publication Date(Web):15 November 2017
DOI:10.1016/j.solener.2017.09.014
•Cation-mixed methylammonium and formamidinium perovskite (MA1−xFAxPbI3) is made.•The cation-mixed perovskite has better crystallinity and larger grain than MAPbI3.•MA1−xFAxPbI3 has less defects and longer charge carrier lifetime than MAPbI3.•Planer perovskite solar cell with MA0.5FA0.5PbI3 gets a high efficiency of 19.41%.•While the perovskite solar cell with pristine MAPbI3 gets an efficiency of 15.95%.Organic lead halide layer is crucial to a high-efficiency planar perovskite solar cell. In order to reduce defects and improve the crystallinity of the perovskite layer, we introduce formamidinium lead iodide (FAPbI3) as crystal seeds to modulate the growth of methylammonium lead iodide (MAPbI3) crystals and form a mixed-cation perovskite layer (MA1−xFAxPbI3) by a facial two-step spin-coating method. The field-emission scanning electron microscopy and X-ray diffraction pattern show the better crystallinity and larger grain for mixed-cation perovskite layer than the pristine MAPbI3 layer. Time-resolved photoluminescence decay measurements indicate that the mixed perovskite layer has less defect and longer lifetime for charge recombination than pristine MAPbI3 layer. Under optimal conditions, the planar perovskite solar cell based on MA0.5FA0.5PbI3 achieves a champion power conversion efficiency (PCE) of 19.41%, while the planar perovskite solar cell based on pristine MAPbI3 obtains a PCE of 15.95% under the same conditions.FAPbI3 improves the quality of mixed perovskite layer and enhances the efficiency of planner solar cell from 15.95% to 19.41%.Download high-res image (105KB)Download full-size image
Co-reporter:Jinghao Huo, Jihuai Wu, Min Zheng, Yongguang Tu, Zhang Lan
Journal of Power Sources 2016 Volume 304() pp:266-272
Publication Date(Web):1 February 2016
DOI:10.1016/j.jpowsour.2015.11.062
•The NiCo2S4/NiS microspheres are synthesized by a two-step hydrothermal method.•The NiCo2S4/NiS shows flower-like morphology and has a large specific surface area.•NiCo2S4/NiS CE exhibits excellent electrocatalytic activity and conductivity.•The DSSC with NiCo2S4/NiS CE obtains a PCE of 8.80% than that of DSSC with Pt CE.The nickel cobalt sulfide/nickel sulfide (NiCo2S4/NiS) microspheres which exhibit flower-like morphologies are synthesized by a two-step hydrothermal method. Then the NiCo2S4/NiS microspheres are deposited on a fluorine doped SnO2 substrate by spin-casting the isopropyl alcohol solution of as-prepared microspheres. The cyclic voltammetry, electrochemical impedance spectroscopy and Tafel tests are employed to measure the electrochemical performance of NiCo2S4/NiS counter electrode. The NiCo2S4 and NiS all are used to improve the conductivity and electrocatalytic ability of the films, and the NiS can also increase the specific surface area of microspheres. The dye-sensitized solar cells (DSSCs) with the NiCo2S4/NiS counter electrode exhibite a power conversion efficiency of 8.8%, which is higher than that of DSSC with Pt counter electrode (8.1%) under the light intensity of 100 mW cm−2 (AM 1.5 G).
Co-reporter:Pei Zhou, Jihuai Wu, Yongguang Tu, Min Zhen, Jinghao Huo, Yuelin Wei, Zhang Lan
Solar Energy 2016 Volume 137() pp:579-584
Publication Date(Web):1 November 2016
DOI:10.1016/j.solener.2016.08.044
•SnO2 nanosheets are synthesized and used as electron-transporting material.•The surface of SnO2 nanosheets is treated with TiCl4 aqueous solution.•The SnO2 nanosheet-based perovskite solar cell achieves a PCE of 7.81%.Organolead halide perovskite solar cells with mesoporous metal oxide films as support layers have made great achievements in the field of solar cells in recent years. Here, tin oxide (SnO2) nanosheets are prepared by hydrothermal method. The as-synthesized SnO2 nanosheet layer is used as electron-transporting material to replace traditional TiO2 mesoporous layer in perovskite solar cells. The crystallizing time of CH3NH3PbI3 on SnO2 is investigated and optimized as 10 min. The surface of SnO2 nanosheets is treated with TiCl4 aqueous solution, which improves the photovoltaic performance of the perovskite solar cells. The SnO2 nanosheet-based perovskite solar cell achieves excellent photovoltaic parameters: short-circuit current density of 17.58 mA cm−2, open-circuit voltage of 1.01 V, and power conversion efficiency of 7.81%.
Co-reporter:Le-Qing Fan, Ji Zhong, Can-Yang Zhang, Ji-Huai Wu, Yue-Lin Wei
International Journal of Hydrogen Energy 2016 Volume 41(Issue 13) pp:5725-5732
Publication Date(Web):13 April 2016
DOI:10.1016/j.ijhydene.2016.02.052
•VOSO4 and Na2MoO4 were respectively introduced into two PVA–H2SO4 gels.•PVA–H2SO4–VOSO4 GPE works on the side of negative electrode.•PVA–H2SO4–Na2MoO4 GPE works on the side of positive electrode.•Both VOSO4 and Na2MoO4 can produce additional pseudocapacitance in the same cell.•Supercapacitor with PVA–H2SO4–VOSO4|PVA–H2SO4–Na2MoO4 GPEs shows high energy density.Redox additives of VOSO4 and Na2MoO4 were respectively added into two polyvinyl alcohol (PVA)–H2SO4 gels to form two gel polymer electrolytes (GPEs). These two redox-active GPEs were separated by a Nafion 117 membrane and assembled with a pair of activated carbon electrodes to construct quasi-solid-state supercapacitors, in which PVA–H2SO4–VOSO4 and PVA–H2SO4–Na2MoO4 GPEs worked on the sides of the negative and positive electrodes of the supercapacitor, respectively. Cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy techniques were used to evaluate the electrochemical performances of the supercapacitor with optimized PVA–H2SO4–VOSO4 and PVA–H2SO4–Na2MoO4 GPEs. After the introduction of VOSO4 and Na2MoO4, the specific capacitance and energy density of the supercapacitor with PVA–H2SO4–VOSO4|PVA–H2SO4–Na2MoO4 GPEs can reach 543.4 F g−1 and 17.9 Wh kg−1, respectively, which are about four times those of the supercapacitor with a PVA–H2SO4 GPE. The enhanced energy storage is attributed to the reversible Faradaic reactions related to VOSO4 and Na2MoO4 in the corresponding gel polymer electrolytes. In addition, the supercapacitor shows good cyclic durability.
Co-reporter:Min Zheng, Jinghao Huo, Yongguang Tu, Jinbiao Jia, Jihuai Wu and Zhang Lan
RSC Advances 2016 vol. 6(Issue 2) pp:1637-1643
Publication Date(Web):26 Nov 2015
DOI:10.1039/C5RA21878K
3,4-Ethylenedioxy thiophene (EDOT) precursor solution doped by Fe3O4 was spin-casted onto fluorine doped tin oxide (FTO) glass and formed poly(3,4-ethylenedioxy thiophene) (PEDOT)/Fe3O4 hybrid films by an in situ polyreaction. The films were utilized as the counter electrode in dye sensitized solar cells (DSSCs). Photoelectric conversion efficiency (PCE) for DSSCs based on PEDOT/Fe3O4 varied with the content of Fe3O4 in the precursor solution. When the content of Fe3O4 was 2 mg ml−1 in the precursor solution (PEDOT/Fe3O4-2), the best performance (8.69%) was obtained. In comparison, that of a DSSC with a Pt counter electrode is 8.35%. According to the surface microtopography and electrochemical analysis, large active areas, consecutive electronic transmission channels and lower charge transfer resistance could be responsible for the high PCE.
Co-reporter:Pei Zhou, Leqing Fan, Jihuai Wu, Chao Gong, Jinfang Zhang, Yongguang Tu
Journal of Alloys and Compounds 2016 Volume 685() pp:384-390
Publication Date(Web):15 November 2016
DOI:10.1016/j.jallcom.2016.05.287
•NiTe rods grow on Ni foam substrate by a hydrothermal route.•NiTe electrode shows a specific capacitance of 804 F g−1 at 1 A g−1.•AC//NiTe asymmetric supercapacitor exhibits energy density of 33.6 Wh kg−1.Nickel telluride (NiTe) rods are grown on Ni foam substrate by a simple hydrothermal route. The electrochemical properties of NiTe electrode are evaluated by cyclic voltammograms (CV), galvanostatic charge/discharge (GCD) tests. The prepared NiTe electrode shows a specific capacitance of 804 F g−1 at the current density of 1 A g−1 and remarkable cycling stability. In order to improve the energy density and broaden the potential window, an asymmetric supercapacitor containing NiTe as positive electrode and activated carbon (AC) as negative electrode in 3 M KOH electrolyte is assembled. The fabricated asymmetric supercapacitor can work in the voltage range of 0–1.6 V and displays high energy density of 33.6 Wh kg−1 at a power density of 807.1 W kg−1. Additionally, the AC//NiTe asymmetric supercapacitor shows good rate capability and cyclic durability.
Co-reporter:Jihuai Wu, Zhang Lan, Jianming Lin, Miaoliang Huang, Yunfang Huang, Leqing Fan, and Genggeng Luo
Chemical Reviews 2015 Volume 115(Issue 5) pp:2136
Publication Date(Web):January 28, 2015
DOI:10.1021/cr400675m
Co-reporter:Yongguang Tu, Jihuai Wu, Min Zheng, Jinghao Huo, Pei Zhou, Zhang Lan, Jianming Lin and Miaoliang Huang
Nanoscale 2015 vol. 7(Issue 48) pp:20539-20546
Publication Date(Web):12 Nov 2015
DOI:10.1039/C5NR05563F
A compact TiO2 layer is crucial to achieve high-efficiency perovskite solar cells. In this study, we developed a facile, low-cost and efficient method to fabricate a pinhole-free and ultrathin blocking layer based on highly crystallized TiO2 quantum dots (QDs) with an average diameter of 3.6 nm. The surface morphology of the blocking layer and the photoelectric performance of the perovskite solar cells were investigated by spin-coating with three different materials: colloidal TiO2 QDs, titanium precursor solution, and aqueous TiCl4. Among these three treatments, the perovskite solar cell based on the TiO2 QD compact layer offered the highest power conversion efficiency (PCE) of 16.97% with a photocurrent density of 22.48 mA cm−2, a photovoltage of 1.063 V and a fill factor of 0.71. The enhancement of PCE mainly stems from the small series resistance and the large shunt resistance of the TiO2 QD layer.
Co-reporter:Geng-Geng Luo, Kai Fang, Ji-Huai Wu and Jun Mo
Chemical Communications 2015 vol. 51(Issue 62) pp:12361-12364
Publication Date(Web):26 Jun 2015
DOI:10.1039/C5CC03897A
A noble-metal-free molecular dyad was constructed by anchoring a thienyl-expanded BODIPY photosensitizer (PS) to a cobaloxime catalyst, which gives a 2.5-fold increase in the TON, and a 3-fold enhancement in the quantum efficiency as compared to the multicomponent catalytic system for the generation of hydrogen via the reduction of water. The stability of PS was expected to improve by introducing the thienyl moiety into the BODIPY core.
Co-reporter:Jia Dong, Jihuai Wu, Jinbiao Jia, Shaoyun Wu, Pei Zhou, Yongguang Tu, Zhang Lan
Electrochimica Acta 2015 Volume 168() pp:69-75
Publication Date(Web):20 June 2015
DOI:10.1016/j.electacta.2015.03.226
Cobalt selenide (CoSe2) nanorods are prepared by hydrothermal method and used as an efficient Pt-free counter electrode (CE) for dye-sensitized solar cells (DSSCs). Field emission scanning electron microscopy observes that CoSe2 mostly exhibits a nanorod morphology, which facilitates change carrier transfer from their surface to redox electrolyte. Cyclic voltammogram measurement indicates that CoSe2 electrode has larger current density than Pt electrode. Electrochemical impedance spectroscopy shows that the CoSe2 electrode with optimal condition has low series resistance of 8.034 Ω × cm2 and has low charge-transfer resistance of 0.097 Ω·cm2. Under simulated solar light irradiation with intensity of 100 mW·cm−2 (AM 1.5), the DSSC based on the CoSe2 CE achieves a power conversion efficiency of 8.38 %, which is higher than the solar cell based on Pt CE (7.83%).
Co-reporter:Ji Zhong, Le-Qing Fan, Xing Wu, Ji-Huai Wu, Gui-Jing Liu, Jian-Ming Lin, Miao-Liang Huang, Yue-Lin Wei
Electrochimica Acta 2015 Volume 166() pp:150-156
Publication Date(Web):1 June 2015
DOI:10.1016/j.electacta.2015.03.114
•HQ and MB were respectively introduced into two PVA-H2SO4 gels and separated by a Nafion membrane.•PVA-H2SO4-HQ and PVA-H2SO4-MB GPEs work on the sides of the positive and negative electrodes of supercapacitor, respectively.•Both HQ and MB can produce additional pseudocapacitance in the same cell.•The supercapacitor with PVA-H2SO4-HQ|PVA-H2SO4-MB GPEs shows high energy density.Quasi-solid-state supercapacitors were assembled using a pair of activated carbon electrodes and two polyvinyl alcohol (PVA)-H2SO4 gel polymer electrolytes (GPEs) containing respectively redox additives of hydroquinone (HQ) and methylene blue (MB), which were separated by a Nafion 117 membrane in a sandwich-type configuration. PVA-H2SO4-HQ and PVA-H2SO4-MB GPEs worked on the sides of the positive and negative electrodes of the supercapacitor, respectively. The electrochemical performances of the supercapacitor with optimized PVA-H2SO4-HQ and PVA-H2SO4-MB GPEs were evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy techniques. After the introduction of HQ and MB, the supercapacitor with PVA-H2SO4-HQ|PVA-H2SO4-MB GPEs can exhibit high specific capacitance of 563.7 F g−1 and energy density of 18.7 Wh Kg−1, increasing by about fourfold in comparison with a supercapacitor with a PVA-H2SO4 GPE. The improved energy storage is ascribed to the reversible Faradaic reactions related to HQ and MB in the corresponding gel polymer electrolytes. Additionally, the supercapacitor shows excellent cyclic durability with 90.0% capacitance retention after 3000 cycles.
Co-reporter:Jinghao Huo, Min Zheng, Yongguang Tu, Jihuai Wu, Linhua Hu, Songyuan Dai
Electrochimica Acta 2015 Volume 159() pp:166-173
Publication Date(Web):20 March 2015
DOI:10.1016/j.electacta.2015.01.214
•CoS electrode is prepared by repetitive electrophoretic and ion exchange depositions.•The CoS has honeycomb-like structure, good catalytic activity and lower resistances.•DSSC with CoS-4AB obtains a PCE of 7.72%, higher than the cell with Pt electrode.A cobalt sulfide (CoS) thin film is deposited on fluorine doped SnO2 (FTO) glass by repetitive electrophoretic deposition (EPD) and ion exchange deposition (IED), then the thin film is treated with sodium borohydride or/and sulfuric acid solution. The film is used as the counter electrode of dye-sensitized solar cells (DSSCs), and is characterized by field emission scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy and Tafel measurements. The results show that the CoS counter electrode has a honeycomb-like morphology with large specific surface area, good catalytic activity for reduction of I3−, lower charge-transfer and series resistances, which result in the better electrochemical property of CoS counter electrodes. Under a simulated solar light irradiation of 100 mW cm−2, the DSSC based on the CoS counter electrode achieves a power conversion efficiency of 7.72%, thus, synthesized CoS can serve as an efficient Pt-free counter electrode material for DSSCs.
Co-reporter:Junchang Zhao, Jihuai Wu, Ming Zheng, Jinghao Huo, Yongguang Tu
Electrochimica Acta 2015 Volume 156() pp:261-266
Publication Date(Web):20 February 2015
DOI:10.1016/j.electacta.2015.01.045
•A colloid of graphene/titania is prepared, and thus a graphene/titania film is made.•The film shows high porosity, large surface area and small transfer resistance.•The cell with graphene/titania photoanode obtains a conversion efficiency of 7.52%.•Which is increased by 18% compared to the cell with pristine titania electrode.A mixed colloid of graphene and titania is synthesized by a one-step hydrothermal reaction, thus a graphene/titania film photoanode is prepared. The graphene/titania film shows high porosity and large specific surface area, which favors a full adsorption of sensitized dye. On the other hand, the graphene/titania electrode has smaller charge transfer resistance than the pristine titania electrode, which replies that the graphene/titania electrode accelerates electronic transportation and suppresses the charge recombination. Under an optimal condition, the dye-sensitized solar cell based on graphene/titania photoanode achieve a power conversion efficiency of 7.52%, which is increased by 17.7% compared to the cell based on the pristine titania electrode under a simulated solar light irradiation of 100 mW·cm−2.
Co-reporter:Min Zheng, Jinghao Huo, Yongguang Tu, Jihuai Wu, Linhua Hu, Songyuan Dai
Electrochimica Acta 2015 Volume 173() pp:252-259
Publication Date(Web):10 August 2015
DOI:10.1016/j.electacta.2015.05.069
A flowerlike molybdenum sulfide/multi-walled carbon nanotube (MoS2/MWCNT) hybrid is prepared and used as an efficient Pt-free counter electrode (CE) for dye-sensitized solar cells (DSSCs). Field emission scanning electron microscopy observes that the flowerlike MoS2/MWCNTs possess lamellar and large specific surface area, which benefits the enhancement of electrocatalytic activity. Cyclic voltammogram measurement indicates that MoS2/MWCNT CE has larger current density smaller overpotential than MoS2, MWCNT, even Pt CEs. Electrochemical impedance spectroscopy shows that the MoS2/MWCNT with optimal MWCNT content has low charge-transfer resistance of 2.05 Ω × cm2 and series resistance of 1.13 Ω·cm2. Under simulated solar light irradiation with intensity of 100 mW·cm−2 (AM 1.5), the DSSC based on the MoS2/MWCNT CE achieves a power conversion efficiency of 7.50 %, which is comparable with the solar cells based on the Pt CE (7.49%).
Co-reporter:Jia Dong, Jihuai Wu, Jinbiao Jia, Linhua Hu, Songyuan Dai
Solar Energy 2015 Volume 122() pp:326-333
Publication Date(Web):December 2015
DOI:10.1016/j.solener.2015.09.011
•Co0.85Se/MoSe2/MoO3 hybrid is synthesized by a facile hydrothermal reaction method.•Hybrid has a hierarchical architecture with nanoparticles, nanosheets and nanorods.•Hierarchical structure and synergy effect improve catalytic activity and resistances.•DSSC with the hybrid CE achieves efficiency of 7.10%, while with Pt CE gives 6.03%.Cobalt selenide/molybdenum selenide/molybdenum oxide (Co0.85Se/MoSe2/MoO3) ternary hybrid is synthesized by a facile hydrothermal method and used as efficient Pt-free counter electrode (CE) for dye-sensitized solar cells (DSSCs). Field emission scanning electron microscopy observes that Co0.85Se/MoSe2/MoO3 possesses hierarchical architecture with one-dimensional (1D) nanorods, two-dimensional (2D) nanosheet and three-dimensional (3D) nanoparticle. Cyclic voltammogram indicates that Co0.85Se/MoSe2/MoO3 hybrid have larger current density than sputtered Pt electrode. Electrochemical impedance spectroscopy shows that cooperation among Co0.85Se, MoSe2 and MoO3 reduces series resistance and charge transfer resistance. The DSSC based on Co0.85Se/MoSe2/MoO3 CE achieves a power conversion efficiency of 7.10%, which is higher than that of the DSSC based on sputtered Pt CE (6.03%).
Co-reporter:Min Zheng, Jinghao Huo, Binguo Chen, Yongguang Tu, Jihuai Wu, Linhua Hu, Songyuan Dai
Solar Energy 2015 Volume 122() pp:727-736
Publication Date(Web):December 2015
DOI:10.1016/j.solener.2015.10.001
•Pt–Co and Pt–Ni binary alloy hollow nanospheres are synthesized by solution reaction.•The binary alloys on PEDOT:PSS show high conductivity and electrocatalytic activity.•The DSSCs with Pt–Co and Pt–Ni CEs achieve PCE of 9.027% and 8.23%, respectively.•The both PCEs are higher than the PCE for the DSSC with Pt CE (7.96%).Binary alloy platinum–cobalt (Pt–Co) and platinum–nickel (Pt–Ni) hollow nanospheres are prepared by using a simple solution reaction method. Poly(3,4-ethylenedioxy thiophene):polystyrene sulfonate (PEDOT:PSS) as supported layer further enhance the binary platinum alloy electrochemical properties. The prepared binary platinum alloys are observed with hollow nanosphere structure. The cyclic voltammogram and electrochemical impedance spectroscopy measurement indicate that Pt–Co and Pt–Ni hollow nanospheres on PEDOT:PSS (PC-PP and PN-PP) electrodes have high conductivity and catalytic performance. Under simulated white solar light irradiation with intensity of 100 mW cm−2 (AM 1.5), the dye-sensitized solar cells (DSSCs) based on PCPP and PNPP counter electrodes achieve power conversion efficiencies of 9.02% and 8.23%, respectively, which are higher than the efficiency for the DSSC based on Pt counter electrode (7.96%).
Co-reporter:Jihuai Wu, Yuelin Wei, Taohai Li, Yunfang Huang, Miaoliang Huang, Jianming Lin
Ceramics International 2015 Volume 41(Issue 3) pp:3839-3844
Publication Date(Web):April 2015
DOI:10.1016/j.ceramint.2014.11.060
H2NiTi4O10/TiO2 intercalated compound is fabricated by successive intercalation reactions of H2NiTi4O10 with an n-C6H13NH2/C2H5OH mixed solution and an acid TiO2 sol, followed by irradiating with a high-pressure mercury lamp. H2NiTi4O10, a layered perovskite type compound with TiO2-loading, exhibits a high photocatalytic activity for degradation of methyl orange under ultraviolet and/or visible light irradiation. The experimental results shows that methyl orange is degraded with the decomposition ratio of 59% by using H2NiTi4O10/TiO2 as photocatalyst under visible light (λ>420 nm) irradiation for 120 min. The H2NiTi4O10/TiO2 compound possesses higher photocatalytic activity than the commercial titania powder (Degussa P-25) which shows the decomposition ratio only 24% under the same condition.
Co-reporter:Le-Qing Fan, Gui-Jing Liu, Can-Yang Zhang, Ji-Huai Wu, Yue-Lin Wei
International Journal of Hydrogen Energy 2015 Volume 40(Issue 32) pp:10150-10157
Publication Date(Web):24 August 2015
DOI:10.1016/j.ijhydene.2015.06.061
•Flower-like MoS2/C composite was prepared by hydrothermal method.•MoS2/C composite has higher specific surface area and electrical conductivity than pure MoS2 and carbon.•Specific capacitance of MoS2/C composite is higher than that of single component.•MoS2/C-based supercapacitor exhibits high rate capability and long cyclic durability.A mesoporous molybdenum disulfide/carbon (MoS2/C) composite with flower-like morphology resulting from the decoration of carbon by MoS2 interlaced nanosheets was synthesized by a facile hydrothermal route, and utilized for the electrode material of supercapacitor. The morphologies and structures of materials were characterized by field emission scanning electron microscopy, X-ray diffraction, Raman spectrum and N2 adsorption–desorption isotherm. Electrochemical properties of materials were evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy tests of two-electrode supercapacitors. The results indicate that the complex of carbon and MoS2 can increase the electrical conductivity and can get thinner MoS2 nanosheets leading to the increment of specific surface area, which result in the improvement in the electrochemical performances of material. The specific capacitance of MoS2/C composite reaches 201.4 F g−1 at a current density of 0.2 A g−1 in a two-electrode supercapacitor, which is higher than those of pure MoS2 and carbon. Additionally, the MoS2/C-based supercapacitor exhibits high rate capability and long cyclic durability.
Co-reporter:Jinghao Huo, Jihuai Wu, Min Zheng, Yongguang Tu and Zhang Lan
RSC Advances 2015 vol. 5(Issue 101) pp:83029-83035
Publication Date(Web):21 Sep 2015
DOI:10.1039/C5RA17026E
CoMoO4/Co9S8 hybrid nanotubes were fabricated by a simple two-step hydrothermal method, which was similar to that for preparing Co9S8 nanotubes. Then the CoMoO4/Co9S8 nanotubes were coated onto fluorine-doped tin oxide glass to fabricate a counter electrode (CE) by spin-casting. Field emission scanning electron microscopy images show that the introduction of CoMoO4 to Co9S8 makes the surface of the CoMoO4/Co9S8 nanotubes rougher. Cyclic voltammetry shows that the electrocatalytic activity of the CoMoO4/Co9S8 CE is similar to that of a Pt CE when the (NH4)2MoO4 content was 60 wt%. Meanwhile, the electrochemical impedance spectroscopy and Tafel measurements demonstrated that the CoMoO4/Co9S8 CE had smaller values of Rs and Rct than a Pt CE. The dye-sensitized solar cells assembled with a CoMoO4/Co9S8 CE achieved excellent values of open-circuit voltage (0.743 V), short-circuit current density (17.276 mA cm−2), fill factor (0.670) and a wonderful power conversion efficiency (8.60%), which is higher than that of DSSCs with a Co9S8 CE (7.69%) or a Pt CE (8.13%) under the light intensity of 100 mW cm−2 (AM 1.5 G).
Co-reporter:Qin Liu;Jihuai Wu;Zhang Lan;Min Zheng;Gentian Yue;Jianming Lin ;Miaoliang Huang
Polymer Engineering & Science 2015 Volume 55( Issue 2) pp:322-326
Publication Date(Web):
DOI:10.1002/pen.23900
A microporous hybrid polymer of poly(acrylic acid)-g-poly(ethylene glycol)/polyaniline (PAA-g-PEG/PANI) is synthesized by a two-step solution polymerization method. The influence of aniline concentration on the conductivity of PAA-g-PEG/PANI gel electrolyte is discussed, when the concentration of aniline is 0.66 wt%, the conductivity of PAA-g-PEG/PANI gel electrolyte is 11.50 mS cm−1. Using this gel electrolyte as host, a quasi solid state dye-sensitized solar cell (QS-DSSC) is assembled. The QS-DSSC based on this gel electrolyte achieves a power conversion efficiency of 6.38% under a simulated solar illumination of 100 mW cm−2 (AM 1.5). POLYM. ENG. SCI., 55:322–326, 2015. © 2014 Society of Plastics Engineers
Co-reporter:Le-Qing Fan, Ji Zhong, Ji-Huai Wu, Jian-Ming Lin and Yun-Fang Huang
Journal of Materials Chemistry A 2014 vol. 2(Issue 24) pp:9011-9014
Publication Date(Web):23 Apr 2014
DOI:10.1039/C4TA01408A
A redox-active gel polymer electrolyte was prepared by introducing KI/VOSO4 redox additives into a polyvinyl alcohol–H2SO4 gel electrolyte for application in a quasi-solid-state electric double-layer capacitor (EDLC) based on activated carbon. The EDLC obtained had a high electrode-specific capacitance of 1232.8 F g−1 and a high energy density of 25.4 W h kg−1; these values are higher than that of an EDLC with a conventional gel electrolyte. The improved energy storage is attributed to Faradaic pseudocapacitance related to the redox-active ions in the gel polymer electrolyte.
Co-reporter:Yaoming Xiao, Gaoyi Han, Yanping Li, Miaoyu Li and Jihuai Wu
Journal of Materials Chemistry A 2014 vol. 2(Issue 40) pp:16856-16862
Publication Date(Web):21 Aug 2014
DOI:10.1039/C4TA03658A
Lead-doped TiO2 nanofibers (TNFs) are fabricated by using an electrospun method, followed by the in situ preparation of perovskite-sensitized photoanode for use in perovskite solar cells (PSC). The electrospun TNFs can provide direct pathways for the rapid collection and transmission of photogenerated electrons. The photoanode based on the in situ method shows not only excellent contacting between the TNF and perovskite, but also abundant perovskite filling in it. These can be conducive not only to the separation and transmission of the electron and hole, but also to the absorption and utilization of sunlight. Finally, a high performance PSC with the cell efficiency of 9.03% is obtained without any hole transporting materials.
Co-reporter:Lanfang Que, Zhang Lan, Wanxia Wu, Jihuai Wu, Jianming Lin, Miaoliang Huang
Journal of Power Sources 2014 Volume 266() pp:440-447
Publication Date(Web):15 November 2014
DOI:10.1016/j.jpowsour.2014.05.022
•3D networks of single crystalline TiO2 nanowire membranes were grown on Ti foils.•Self-standing TiO2 nanowire membranes were used to fabricate front-side photoanodes.•The highest power conversion efficiency of DSCs could attain to 8.05%.High-efficiency dye-sensitized solar cells (DSCs) based on 3D networks of ultra-long single crystalline TiO2 nanowires are fabricated. By hydrothermal reaction of Ti foils in alkali aqueous solution, following ion exchange and high temperature sintering processes, the ultra-long single crystalline TiO2 nanowires can be prepared. Due to long enough of the TiO2 nanowires, they not only form 1D arrays perpendicular to Ti foils, but also extend to form 3D network structure on the top-side of the arrays. By optimizing the hydrothermal duration at 24 h, the formed TiO2 nanowire membrane based front-side illuminated photoanode shows enhanced dye-loading and light scattering abilities and excellent charge transport properties. So the DSC with this photoanode can attain to the highest power conversion efficiency about 8.05%.
Co-reporter:Jihuai Wu, Ziying Tang, Yunfang Huang, Miaoliang Huang, Haijun Yu, Jianming Lin
Journal of Power Sources 2014 Volume 257() pp:84-89
Publication Date(Web):1 July 2014
DOI:10.1016/j.jpowsour.2014.01.090
•Pt nanotubes (PNTs) are grown on FTO substrates by polycarbonate template method.•The PNTs show 1D structure, lower resistance, and good electrochemical activity.•The dye-sensitized solar cell with PNTs electrode achieves an efficiency of 9.05%.•The efficiency is increased by 25.5% compared to the DSSC with usual Pt electrode.Platinum nanotubes (PNTs) are directly grown on fluorine-doped tin oxide substrates by a facile polycarbonate template method. Morphology observation and electrochemical measurements indicate that the PNTs show a one-dimensional structure, lower charge-transfer resistance, larger exchange current density and higher electrocatalytic activity for iodide/triiodide redox reaction. Using the PNT as counter electrode and MgO as block layer on TiO2 film, the fabricated dye-sensitized solar cell achieves a light-to-electric energy conversion efficiency of 9.05% under a simulated solar light irradiation of 100 mW cm−2, the efficiency is increased by 25.5% compared to that of DSSC based on conventional Pt counter electrode. Higher efficiency for the PNT electrode is due its one-dimensional nanostructure, large surface area and good electrochemical activity to iodide/triiodide couple.
Co-reporter:Yaoming Xiao, Jihuai Wu, Jianming Lin, Miaoliang Huang, Leqing Fan, Zhang lan, Gaoyi Han, Sidian Li
Electrochimica Acta 2014 Volume 117() pp:1-8
Publication Date(Web):20 January 2014
DOI:10.1016/j.electacta.2013.11.096
•A new p-n junction is prepared and used in the large-area flexible DSSC as an anode.•The p-n junction formes a directional pathway for the charge separation and electron transport.•The p-n junction showes low charge-transfer resistance and high effective electron lifetime.•The efficiency of the large-area flexible DSSC reaches 6.51% based on the p-n junction.A p-n junction of poly (3,4-ethylenedioxythiophene) (PEDOT) - dye-sensitized TiO2 is introduced into the large-area flexible dye-sensitized solar cell (DSSC) as an anode. This p-n junction is fabricated using a cyclic voltammetry electropolymerization of PEDOT onto a Ti foil substrate, and then treated in the aqueous ammonia, finally subjected to coating TiO2 by a doctor-scraping technique, all of preparations and treatments are carried out under low temperature. The obtained p-n junction forms a single directional pathway for electron transport which benefites the charge separation. The large-area (10 cm2) flexible DSSC with the p-n junction demonstrates an enhanced photovoltaic conversion efficiency of up to 6.51% compared to 4.89% for the DSSC without the p-n junction due to its low series resistance and charge-transfer resistance, high effective electron lifetime for recombination. As a result, the DSSC fabricated using the p-n junction can be suitable for high powered DSSC applications.
Co-reporter:Gentian Yue, Furui Tan, Fumin Li, Chong Chen, Weifeng Zhang, Jihuai Wu, Qinghua Li
Electrochimica Acta 2014 Volume 149() pp:117-125
Publication Date(Web):10 December 2014
DOI:10.1016/j.electacta.2014.10.075
•The NiS/PANI/Ti composite were first time prepared and employed as counter electrode (CE) for Pt-free flexible DSSC.•The NiS/PANI/Ti CE showed great electrocatalytic ability and low resistance of 1.48 ± 0.02 Ω · cm2 for I–/I3–electrolyte.•The power conversion efficiency of the FDSSC reached 7.35% based on the NiS/PANI/Ti CE.A novel titanium foil substrate strategy for the synthesis of high electrocatalytic activity nickel sulfide/polyaniline/titanium (NiS/PANI/Ti) composite film with one-dimensional (1D) net-work structure by using an in situ electropolymerization route, and proposed as platinum (Pt)-free counter electrode (CE) catalyst for flexible dye-sensitized solar cells (FDSSCs). The photovoltaic performance of the FDSSC based on the NiS/PANI/Ti CE exhibits Jsc of 14.56 mA · cm−2, Voc of 0.743 V, FF of 0.68, and corresponding to the η of 7.35%, much higher photoelectric conversion efficiency than that of Pt/Ti CE (6.24%). The NiS/PANI/Ti CE with 1D net-work structure is characterized by using the scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization plots. The NiS/PANI/Ti CE presents multiple functions, i.e., excellent conductivity, great electrocatalytic ability for iodine/triiodine, and lower charge transfer resistance of 1.48 ± 0.02 Ω · cm2 compared to the Pt/Ti electrode (2.25 ± 0.02 Ω · cm2). The photocurrent-photovoltage (J-V) character curves are further used to calculate theoretical short-current densities and open-circuit voltage of the devices. Therefore, the NiS/PANI/Ti CE with 1D net-work structure can be considered as a promising and efficient CE for FDSSCs.Much higher photovoltaic performance of flexible dye-sensitized solar cell with NiS/PANI/Ti counter electrode as well as that of Pt configuration device.
Co-reporter:Gentian Yue, Xingping Ma, Qiwei Jiang, Furui Tan, Jihuai Wu, Chong Chen, Fumin Li, Qinghua Li
Electrochimica Acta 2014 Volume 142() pp:68-75
Publication Date(Web):1 October 2014
DOI:10.1016/j.electacta.2014.07.107
•The (G-P-A) MoS2/SWCNTs composite were first time prepared and employed as counter electrode (CE) in Pt-free DSSC;.•The (G-P-A) MoS2/SWCNTs CE showed the low Rct of 1.46 Ω·cm2;.•The photo-electric conversion efficiency of the DSSC reached 8.14% based on the (G-P-A) MoS2/SWCNTs CE.A flower-like structure complexes of molybdenum disulfide/single-wall carbon nanotubes (MoS2/SWCNTs) are for the first time synthesized with glucose and poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS) assisted (G-P-A) by the use of an in situ hydrothermal route, and proposed as counter electrode (CE) catalyst for Pt-free dye-sensitized solar cells (DSSCs). The DSSC assembled with the (G-P-A) MoS2/SWCNTs CE exhibits a high photo-electric conversion efficiency of 8.14% under the illumination of 100 mW·cm−2, comparable to that of the DSSC Pt-based (7.78%). Furthermore, the surface morphology of the (G-P-A) MoS2/SWCNTs complexes with flower-like structure is confirmed by using the scanning and transmission electron microscopes (SEM). The superior structural characteristic along with 3D large interconnected interstitial volume is advantageous fast mass transport for the electrolyte, and enables the (G-P-A) MoS2/SWCNTs CE to speed up the reduction of triiodide to iodide. The electrochemical performance of the sample is analyzed from cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It indicates that the (G-P-A) MoS2/SWCNTs CE possesses excellent electrocatalytic activity in iodide/triiodide electrolyte and lower charge transfer resistance of 1.46 Ω·cm2 compared to the Pt electrode (2.44 Ω·cm2). Sum up, the (G-P-A) MoS2/SWCNTs CE can be considered as a promising alternative CE for Pt-free DSSCs.Much higher photovoltaic performance of dye-sensitized solar cell with (G-P-A) MoS2/SWCNTs counter electrode than that of Pt configuration device.
Co-reporter:Gentian Yue, Xin’an Zhang, Lei Wang, Furui Tan, Jihuai Wu, Qiwei Jiang, Jianming Lin, Miaoliang Huang, Zhang Lan
Electrochimica Acta 2014 Volume 129() pp:229-236
Publication Date(Web):20 May 2014
DOI:10.1016/j.electacta.2014.02.109
•Pt-free dye-sensitized solar cells.•The nanographite/PPy composite film showed high catalytic activity as well as Pt electrode.•The enhanced catalytic activity was attributed to increased active sites.•The DSSC based on the nanographite/PPy electrode showed a high photovoltaic performance.Nanographite/polypyrrole (NG/PPy) composite film was successfully prepared via in situ polymerization on rigid fluorine-doped tin oxide substrate and served as counter electrode (CE) for dye-sensitized solar cells (DSSCs). The surface morphology and composition of the composite film were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra and Fourier transform infrared spectroscopy (FTIR). The electrochemical performance of the NG/PPy electrode was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results of CV and EIS revealed that the NG/PPy electrode possessed excellent electrocatalytic activity for the reduction reaction of triiodide to iodide and low charge transfer resistance at the interface between electrolyte and CE, respectively. The DSSC assembled with the novel NG/PPy CE exhibited an enhanced power conversion efficiency of 7.40% under full sunlight illumination as comparing to that of the DSSC based on sputtered-Pt electrode. Thus, the NG/PPy CE could be premeditated as a promising alternative CE for low-cost and high- efficient DSSCs.Much higher photovoltaic performance of dye-sensitized solar cell with nanographite/PPy counter electrode as well as that of Pt configuration device.
Co-reporter:Leqing Fan, Yuelin Wei, Yinghan Cheng, Yunfang Huang, Sancun Hao, Jihuai Wu
International Journal of Hydrogen Energy 2014 Volume 39(Issue 15) pp:7747-7752
Publication Date(Web):15 May 2014
DOI:10.1016/j.ijhydene.2014.02.172
•A novel perovskite intercalated nanomaterial HLaNb2O7/(Pt, TiO2) is prepared.•The gallery height of HLaNb2O7/(Pt, TiO2) is less than 0.6 nm.•Hydrogen evolution of this photocatalyst is 240 cm3 h−1 g−1 in methanol solution.•Catalytic activity of HLaNb2O7/TiO2 is better than TiO2 and is enhanced by Pt assisting.A novel perovskite intercalated nanomaterial HLaNb2O7/(Pt, TiO2) is fabricated by successive intercalated reaction of HLaNb2O7 with [Pt(NH3)4]Cl2 aqueous solution, n-C6H13NH2/C2H5OH organic solution and acidic TiO2 colloid solution, followed by ultraviolet light irradiation. The gallery height and the band gap energy of HLaNb2O7/(Pt, TiO2) is less than 0.6 nm and 3.14 eV, respectively. The photocatalytic activity of HLaNb2O7/TiO2 is superior to that of unsupported TiO2 and is enhanced by the co-incorporation of Pt. The photocatalytic hydrogen evolution based on HLaNb2O7/(Pt, TiO2) is 240 cm3 h−1 g−1 using methanol as a sacrificial agent under irradiation with wavelength more than 290 nm from a 100-W mercury lamp. High photocatalytic activity of HLaNb2O7/(Pt, TiO2) may be due to the host with rare earth La element and perovskite structure, the quantum size effect of intercalated semiconductor and the coupling effect between host and guest.
Co-reporter:Zhang Lan;Jihuai Wu;Suwen Gao;Jianming Lin;Miaoliang Huang ;Xiaomin Chen
Polymers for Advanced Technologies 2014 Volume 25( Issue 3) pp:343-346
Publication Date(Web):
DOI:10.1002/pat.3246
Polyaniline (PAn) nanobelts were synthesized by simply mixing aniline and hydrochloric acid aqueous solution with ammonium peroxydisulfate and hydrochloric acid aqueous solution at room temperature without any templates. The PAn nanobelt paste with polytetrafluoroethylene as binder is proper for low-cost and efficient casting processes such as doctor blade method, screen printing, spin-casting, and even roll-to-roll painting. The porous network structure of the PAn nanobelt counter electrode was obtained after drying the paste on the conductive glass. The as-prepared PAn nanobelt counter electrode showed nearly equivalent electrochemical catalytic activity as that of thermal decomposed Pt counter electrode, owing to the well-connected conductive network and high active surface area. The power conversion efficiency of dye-sensitized solar cell with PAn nanobelt counter electrode attained 90% of the value of the cell with Pt counter electrode. Copyright © 2014 John Wiley & Sons, Ltd.
Co-reporter:Gentian Yue, Dawei Zhang, Fuirui Tan, Jihuai Wu, Fumin Li, Chong Chen, Zhang Lan
Synthetic Metals 2014 Volume 197() pp:204-209
Publication Date(Web):November 2014
DOI:10.1016/j.synthmet.2014.09.018
•PEDOT/Pt film is synthesized and employed as the counter electrode in DSSC.•The counter electrode prepared by an electropolymerization method.•PEDOT/Pt electrode is provided with high cathodic current density and the low Rct of 1.31 Ω cm2.•The power conversion efficiency of DSSC with PEDOT/Pt electrode achieved 7.86%.Composite film of poly(3,4-ethylenedioxythiophene)/platinum (PEDOT/Pt) with high efficient is electrodeposited onto rigid fluorine-doped tin oxide substrate by using a facile approach of one step electrochemical polymerization, and its application as counter electrode (CE) in dye-sensitized solar cell (DSSC). The DSSC based on the PEDOT/Pt counter electrode exhibited a high power conversion efficiency of 7.86% under illumination of 100 mW cm−2, which is higher 13.09% than that of the DSSC based on Pt electrode (6.95%). The extensive electrochemical analyses for the PEDOT/Pt CE made from cyclic voltammetry, electrochemical impedance spectroscopy measurements, and Tafel curves reveal that the PEDOT/Pt hybrid CE possesses high electrocatalytic activity for the reduction of triiodide to iodide and low charge-transfer resistance on the counter electrode–electrolyte interface. Therefore, the PEDOT/Pt CE can be considered as a promising alternative CE for DSSCs.Much higher photovoltaic performance of dye-sensitized solar cell with PEDOT/Pt counter electrode as well as that of Pt configuration device.
Co-reporter:Zhang Lan;Xiaoping Zhang;Shi Jie Kang
Journal of Materials Science: Materials in Electronics 2014 Volume 25( Issue 2) pp:673-677
Publication Date(Web):2014 February
DOI:10.1007/s10854-013-1629-9
Sb2S3-sensitized TiO2 films were prepared with chemical bath deposition (CBD) method. The influences of acetone and acetic acid solvents on the morphologies of Sb2S3-sensitized TiO2 films and their light absorbing ability were investigated. Furthermore, photoelectrochemical solar cells containing Sb2S3-sensitized TiO2 photoanodes, polyaniline, and Pt counter electrodes were prepared to investigate the photovoltaic performance of these Sb2S3-sensitized TiO2 films. It was found that the Sb2S3-sensitized TiO2 photoanode prepared with CBD method in the solution containing acetic acid showed higher light absorption in short-wavelength region, lower charge transfer resistance and longer electron lifetime compared with that of the one prepared with CBD method in the solution containing acetone, resulting in better photovoltaic performance.
Co-reporter:Zhang Lan;JiHuai Wu;JianMing Lin;MiaoLiang Huang
Science China Chemistry 2014 Volume 57( Issue 6) pp:888-894
Publication Date(Web):2014 June
DOI:10.1007/s11426-013-5052-0
A new kind of photoactive electrodes with nanocrystalline TiO2 (nano-TiO2) secondary structure is successfully prepared via a simple method of adding a small amount of TiCl4 2-propanol solution in conventional nano-TiO2 paste to form micro-sized nano-TiO2 aggregates. The benefits of this special structure include improved optical absorption, increased light scattering ability, and enhanced electron transport and collection efficiency. Dye-sensitized solar cells (DSCs) based on these photoactive electrodes show improved performance. The power conversion efficiency of the cells can be increased from 5.03% to 7.30% by substituting 6 μm conventional nano-TiO2 thin film with the same thickness of as-prepared nano-TiO2 aggregates film in the photoactive electrodes. A higher power conversion efficiency of the cells can be obtained by further increasing the thickness of the nano-TiO2 aggregates film.
Co-reporter:Yaoming Xiao, Jihuai Wu, Jengyu Lin, Gentian Yue, Jianming Lin, Miaoliang Huang, Yunfang Huang, Zhang Lan and Leqing Fan
Journal of Materials Chemistry A 2013 vol. 1(Issue 44) pp:13885-13889
Publication Date(Web):12 Sep 2013
DOI:10.1039/C3TA12972A
Multi-wall carbon nanotubes (MWCNTs) were deposited on a titanium (Ti) foil substrate by using electrophoresis, then a nano-corallines nickel sulfide (NiS) was deposited on the MWCNTs by using a pulse potentiostatic method. The high performance NiS/MWCNT/Ti hybrid film was firstly used as a Pt-free counter electrode (CE) in dye-sensitized solar cells (DSSCs). The surface of MWCNTs was wrapped with a nano-corallines NiS thin film of ∼45 nm in thickness. Under full sunlight illumination (100 mW cm−2, AM 1.5 G), DSSCs with a NiS/MWCNT/Ti CE achieved an enhanced photovoltaic conversion efficiency of 7.90%, while DSSCs with a Pt/Ti CE obtained the efficiency of 6.36%. The characterization of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) indicated that nano-corallines NiS had high electrocatalytic activity for I3− reduction, MWCNTs had high specific surface area and low resistance, and the synergistic effect of NiS and MWCNTs endowed the superior features of the hybrid film. Therefore, the NiS/MWCNT/Ti CE can be used as a promising alternative CE in low-cost and large-scale DSSCs.
Co-reporter:Guanglu Shang, Jihuai Wu, Miaoliang Huang, Zhang Lan, Jianming Lin, Qin Liu, Min Zheng, Jinghao Huo and Lu Liu
Journal of Materials Chemistry A 2013 vol. 1(Issue 34) pp:9869-9874
Publication Date(Web):07 Jun 2013
DOI:10.1039/C3TA11946G
Three-dimensional hierarchical titania bur-like microspheres (TiO2 BMs) composed of nanowires were synthesized by a hydrothermal method, and possess a specific surface area of 114 m2 g−1 and a main pore size of 6 nm. The one-dimensional nanowire ensures faster electron transport and a longer electron recombination time than titania nanoparticles (TiO2 NPs). Therefore, a film based on the TiO2 BMs exhibits excellent light scattering properties and thus enhances light harvesting efficiency. Using a TiO2 BM film as a scattering layer on the top of a compact TiO2 NP film, the double layered dye-sensitized solar cell (DSSC) shows a power conversion efficiency of 7.31%, indicating a 10.2% and 15.1% improvement compared to the DSSCs based on TiO2 NP and TiO2 BM single films, respectively.
Co-reporter:Yaoming Xiao, Jihuai Wu, Jeng-Yu Lin, Sheng-Yen Tai and Gentian Yue
Journal of Materials Chemistry A 2013 vol. 1(Issue 4) pp:1289-1295
Publication Date(Web):05 Nov 2012
DOI:10.1039/C2TA00073C
Because of the large specific surface area and superior electrical conductivity of multi-wall carbon nanotubes (MWCNTs) and the high electrocatalytic activity of cobalt sulfide (CoS), CoS/MWCNT hybrid films are deposited onto Ti foil substrates by sequential electrophoresis and pulse potentiostatic electrodeposition. Field-emission scanning electron microscopy observes that the surface of the MWCNTs is wrapped with a nano-honeycomb CoS thin film of ∼55 nm in thickness. Cyclic voltammograms, electrochemical impedance spectroscopy, and Tafel polarization characterization indicate that the CoS/MWCNT/Ti counter electrode (CE) has better electrocatalytic activity for I3− reduction than Pt CE. Under full sunlight illumination (100 mW cm−2, AM 1.5 G), the dye-sensitized solar cell based on the CoS/MWCNT/Ti CE achieves a power conversion efficiency of 8.05%, which exceeds that of the device based on Pt/Ti CE (6.39%).
Co-reporter:Gentian Yue, Jihuai Wu, Yaoming Xiao, Miaoliang Huang, Jianming Lin and Jeng-Yu Lin
Journal of Materials Chemistry A 2013 vol. 1(Issue 4) pp:1495-1501
Publication Date(Web):19 Nov 2012
DOI:10.1039/C2TA00860B
A high porous molybdenum sulfide–carbon (MoS2–C) hybrid film was prepared by using an in situ hydrothermal route. The MoS2–C hybrid film served as a low-cost and high efficient platinum-free counter electrode for a dye-sensitized solar cell (DSSC). The cyclic voltammetry, electrochemical impedance spectroscopy and Tafel curve analysis indicate that the MoS2–C electrode possesses low charge transfer resistance on the electrolyte–electrode interface, high electrocatalytic activity and fast reaction kinetics for the reduction of triiodide to iodide at the counter electrode, which is due to large specific surface area and special structure and compositions of MoS2–C film. A DSSC with the novel MoS2–C counter electrode achieve a high power conversion efficiency of 7.69% under standard light illumination, which exceeds that of the DSSC with a Pt counter electrode (6.74%).
Co-reporter:Yaoming Xiao, Jihuai Wu, Jeng-Yu Lin, Gentian Yue, Jianming Lin, Miaoliang Huang, Zhang Lan, Leqing Fan
Journal of Power Sources 2013 Volume 241() pp:373-378
Publication Date(Web):1 November 2013
DOI:10.1016/j.jpowsour.2013.04.091
•PEDOT–PAA–PSS is prepared and used as counter electrode in dye-sensitized solar cell.•The hybrid can store liquid electrolyte and has good electrocatalytic activity.•The efficiency of the solar cell using the dual function electrode reaches 6.35%.A dual function polymer hybrid material poly(3,4-ethylenedioxythiophene) (PEDOT)–poly(acrylic acid) (PAA)–poly(styrenesulfonate) (PSS) was fabricated both as a counter electrode (CE) for I3− reduction and for storage of the liquid electrolyte in quasi-solid-state dye-sensitized solar cells (QS-DSSCs). To enhance the electrocatalytic activity of the nano-PEDOT CE and to improve the ionic conductivity of the three-dimensional (3D) PAA–PSS network, the columnar PEDOT was electropolymerized through the 3D PAA–PSS network. The QS-DSSC showed a high photovoltaic conversion efficiency of 6.35% under full sunlight illumination (100 mW cm−2, AM1.5 G), which reduced to 6.03% after 100 days, indicating this QS-DSSC had a relatively good long-term stability.
Co-reporter:Gentian Yue, Jihuai Wu, Jeng-Yu Lin, Yaoming Xiao, Sheng-Yen Tai, Jianming Lin, Miaoliang Huang, Zhang Lan
Carbon 2013 Volume 55() pp:1-9
Publication Date(Web):April 2013
DOI:10.1016/j.carbon.2012.10.045
Multi-wall carbon nanotubes decorated with tungsten sulfide (MWCNTs-WS2) were synthesized by using a hydrothermal method, and used as a low-cost platinum-free counter electrode for dye-sensitized solar cell (DSSC). Cyclic voltammetry and electrochemical impedance spectroscopy characterizations indicate that the counter electrode has a high catalytic activity for the reduction of triiodide to iodide and a low charge transfer resistance at the electrolyte–electrode interface. A DSSC based on this counter electrode achieves a high power conversion efficiency of 6.41% under a simulated solar illumination of 100 mW cm−2 (AM 1.5). This efficiency is comparable to 6.56% for a DSSC with Pt counter electrode.
Co-reporter:Gentian Yue, Jihuai Wu, Yaoming Xiao, Miaoliang Huang, Jianming Lin, Leqing Fan, Zhang Lan
Electrochimica Acta 2013 Volume 92() pp:64-70
Publication Date(Web):1 March 2013
DOI:10.1016/j.electacta.2012.11.020
A platinum nanoparticles/graphene nanosheets (PtNP/GN) film was prepared on rigid fluorine-doped tin oxide substrate by using a facile one step electrochemical deposition method, and the film was used as counter electrode for dye-sensitized solar cell (DSSC). The cyclic voltammetry, electrochemical impedance spectroscopy and Tafel curves measurements indicated that the PtNP/GN CE has higher conductivity and better electrocatalytic activity for I3−/I− redox reaction, lower charge transfer resistance on the electrolyte/electrode interface for I3−/I− redox reaction than that of Pt electrode, which is due to that the synergistic effect combined platinum nanoparticles with graphene nanosheet intrinsic characteristic. As a result, the DSSC based on the PtNP/GN counter electrode achieved a high power conversion efficiency of 7.88% under AM1.5 illumination of 100 mW cm−2, which is higher 21.04% than that of the DSSC based on Pt electrode.Highlights► A platinum/graphene film was prepared by using a facile electrochemical deposition method. ► A DSSC based on Pt/GN counter electrode achieved a conversion efficiency of 7.88%. ► The high efficiency is due to the synergistic effect combined platinum with graphene.
Co-reporter:Junchang Zhao, Jihuai Wu, Fuda Yu, Xiaoping Zhang, Zhang Lan, Jianming Lin
Electrochimica Acta 2013 Volume 96() pp:110-116
Publication Date(Web):30 April 2013
DOI:10.1016/j.electacta.2013.02.067
A mixed colloid of graphene and titania is synthesized by one-step hydrothermal reaction, thus a graphene/titania film photoanode is prepared. The graphene/titania film shows high porosity and specific surface area, which favors CdS quantum dots deposition on the film. On the other hand, the graphene/titania electrode has smaller electron transfer resistance and lower frequency peak than the pristine titania electrode, which indicates that the electron transport rate is increased by incorporating graphene into titania electrode. Under an optimal condition, the CdS quantum dots-sensitized solar cell based on graphene/titania photoanode achieves a light-to-electric energy conversion efficiency of 1.70%, which is increased by 57% compared with the solar cell based on the pristine titania electrode under a simulated solar light irradiation of 100 mW cm−2.Highlights► A CdS QDs-sensitized solar cell with grapheme/TiO2 photoanode is prepared. ► Graphene/TiO2 electrode has large surface area and small recombination resistance. ► It favors the increase of electron transport and decrease of charge recombination. ► The efficiency of the cell is increased by 57% compared to the cell with TiO2 anode.
Co-reporter:Zhang Lan, Xiaoping Zhang, Jihuai Wu, Jianming Lin, Miaoliang Huang, Huang Zhao
Electrochimica Acta 2013 Volume 108() pp:337-342
Publication Date(Web):1 October 2013
DOI:10.1016/j.electacta.2013.06.121
A novel photoelectrochemical solar cell was prepared by combining a Sb2S3-sensitized photoactive electrode, polyaniline nanobelts and a Pt counter electrode to form sandwich structure. The incident photo-to-current conversion efficiency measurement found that the cell without any sensitizers just showed a very narrow photo-response wavelength region from 300 nm to 400 nm, while the Sb2S3-sensitized cell showed a broad photo-response wavelength region from 275 nm to 600 nm and much higher efficiency in converting ultraviolet light to electricity than in converting visible light. By optimizing chemical bath deposition duration of 2.5 h, the cell showed high photovoltaic performance with 6.92 mA cm−2 short-circuit current density, 1.098 V open-circuit voltage, 0.497 fill factor, and 3.78% power conversion efficiency, being greatly enhanced compared with that of the cell without any sensitizers (1.09 mA cm−2, 0.866 V, 0.477, 0.45%).
Co-reporter:Gentian Yue, Weifeng Zhang, Jihuai Wu, Qiwei Jiang
Electrochimica Acta 2013 Volume 112() pp:655-662
Publication Date(Web):1 December 2013
DOI:10.1016/j.electacta.2013.09.019
•The glucose aided (G-A) preparation of MoS2/CNTs composites were employed as CE in Pt-free DSSC.•The (G-A) MoS2/CNTs* CE showed the low Rct of 1.77 Ω cm2.•The efficiency of the DSSC reached 7.92% based on the (G-A) MoS2/CNTs* CE.In our present study, the composites of molybdenum disulfide/carbon nanotubes (MoS2/CNTs) were synthesized with glucose aided (G-A) by using an in situ hydrothermal route, and proposed as counter electrode (CE) catalyst in the dye-sensitized solar cells (DSSCs) for enhancing electrocatalytic activity toward the reduction of triiodide. The MoS2/CNTs composites with tentacle-like structure were confirmed by using the scanning and transmission electron microscopy. The superior structural characteristics including large active surface area and particularly the unique tentacle-like nanostructure along with 3D large interconnected interstitial volume guaranteed fast mass transport for the electrolyte, and enabled the (G-A) MoS2/CNTs CE to speed up the reduction of triiodide to iodide. The extensive electrochemical studies by the cyclic voltammetry, electrochemical impedence spectroscopy and Tafel measurements indicated that the (G-A) MoS2/CNTs CE possessed superior electrocatalytic activity, great electrochemical stability and impressive low charge transfer resistance on the electrolyte|electrode interface (1.77 Ω cm2) in the triiodide/iodide system compared to the pristine MoS2, MoS2/C and sputtered Pt CEs. The DSSC assembled with the novel (G-A) MoS2/CNTs CE exhibited high power conversion efficiency of 7.92% under the illumination of 100 mW cm−2, comparable to that of the DSSC with the Pt electrode (7.11%).
Co-reporter:Qingbei Li, Jianming Lin, Jihuai Wu, Zhang Lan, Yue Wang, Fuguo Peng, Miaoliang Huang
Journal of Luminescence 2013 Volume 134() pp:59-62
Publication Date(Web):February 2013
DOI:10.1016/j.jlumin.2012.09.014
Doped rare-earth oxide Gd2O3:Sm3+ is prepared and introduced into the TiO2 film in dye-sensitized solar cell (DSSC). Gd2O3:Sm3+, as a luminescence medium, improves light harvest via a downshift luminescence process and increases photocurrent of the DSSC; the rare-earth ion, as a p-type dopant, elevates the energy level of the oxide film and increases the photovoltage of the DSSC. Under a simulated solar light irradiation with intensity of 100 mW cm−2, a DSSC contained Gd2O3:Sm3+ (6% in doping layer) achieves a light-to-electric energy conversion efficiency of 6.72%, which is increased by 12.6% compared with a DSSC lacking Gd2O3:Sm3+.Highlights► Doped RE oxide Gd2O3:Sm3+ is introduced into TiO2 film in dye-sensitized solar cell. ► RE ions increase light harvest via downshift luminescence and thus photocurrent. ► RE ions enhance the energy level of TiO2 film and thus photovoltage. ► Solar cell doped Gd2O3:Sm3+ achieves conversion efficiency of 6.72%, which is increased by 12.6% compared with a solar cell lacking of Gd2O3:Sm3+.
Co-reporter:Yaoming Xiao, Jihuai Wu, Gentian Yue, Jianming Lin, Miaoliang Huang, Leqing Fan, Zhang Lan
Materials Chemistry and Physics 2013 Volume 138(2–3) pp:899-904
Publication Date(Web):15 March 2013
DOI:10.1016/j.matchemphys.2012.12.080
Large-area flexible dye-sensitized solar cells (DSSCs) based on nanocrystalline TiO2/Ti anodes on the Ti foils and platinum/single-wall carbon nanotube (Pt/SWCNT) counter electrodes on the indium-doped tin oxide coated polyethylene naphthalate (ITO/PEN) substrates, were successfully assembled with Ti grids. The resistance of the DSSC could be observably reduced with the Ti grid, which could enhance the fill factor and the efficiency of the DSSC. Ultraviolet-O2 treatment of the TiO2/Ti anode could improve the efficiency of the DSSC, owing to that the passivated Ti foil was enhanced by the ultraviolet-O2 treatment. Based on the optimal preparation conditions, a large-area (40 cm2) flexible DSSC with efficiency of 5.29% was achieved under natural light intensity of 55 mW cm−2 measured outdoors.Highlights► A large-area flexible Pt/SWCNT counter electrode was prepared based on the Ti grid. ► A large-area flexible TiO2/Ti anode was fabricated on the Ti foil. ► The efficiency was increased by 10.21% using the ultraviolet-O2 treatment. ► The efficiency of the large-area (40 cm2) flexible DSSC reached 5.29%.
Co-reporter:GenTian Yue;JiHuai Wu;YaoMing Xiao;JianMing Lin
Science Bulletin 2013 Volume 58( Issue 4-5) pp:559-566
Publication Date(Web):2013 February
DOI:10.1007/s11434-012-5352-3
A counter electrode for dye-sensitized solar cell (DSSC) was prepared by coating poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) with high transparency and adhesion on a conducting FTO glass at low temperature. The surface morphology, conductivity, sheet resistance, redox properties and photoelectric properties of the PEDOT:PSS/carbon electrodes were observed using scanning electron microscopy, a four-probe tester and a CHI660D electrochemical measurement system. The experimental results showed that DSSCs had the best photoelectric properties for PEDOT:PSS/carbon counter electrodes annealed at 80°C under vacuum conditions. The overall energy conversion efficiency of the DSSC with PEDOT:PSS/carbon counter electrode and barrier layer reached 7.61% under irradiation from a simulated solar light with intensity of 100 mW/cm2 (AM 1.5). The excellent photoelectric properties, simple preparation procedure and low cost allow the PEDOT:PSS/carbon electrode to be a credible alternative electrode for use in DSSCs.
Co-reporter:Ziying Tang, Jihuai Wu, Min Zheng, Jinhao Huo, Zhang Lan
Nano Energy 2013 Volume 2(Issue 5) pp:622-627
Publication Date(Web):September 2013
DOI:10.1016/j.nanoen.2013.07.014
•A microporous Pt film is prepared by a facile rapid thermal decomposition method.•The film has larger area, better catalysis and lower resistance than current Pt film.•The dye-sensitized solar cell using the film obtains a conversion efficiency of 8.15%.•The efficiency is increased by 21.28% compared to the cell with current Pt electrode.A microporous platinum film is prepared by a facile rapid thermal decomposition method. Scanning electronic microscope observes a large amount of interconnected and uniform micropores with a pore diameter of 100–150 nm on the microporous platinum electrode. The cyclic voltammetry measurements indicate that the microporous platinum electrode has higher catalytic activity and smaller resistance than the conventional platinum electrode does. By using the microporous platinum film as counter electrode, a dye-sensitized solar cell (DSSC) is fabricated, the DSSC achieves a high light-to-electric energy conversion efficiency of 8.15% under a simulated solar light irradiation with a intensity of 100 mW cm−2. The efficiency is increased by 21.28% compared to that of the DSSC with conventional platinum counter electrode.Photocurrent–voltage curves of DSSCs with conventional and microporous Pt counter electrodes. Insert are the SEM images of conventional and microporous Pt counter electrodes.
Co-reporter:Haijun Yu; Jihuai Wu; Jianming Lin;Dr. Leqing Fan;Miaoliang Huang;Youzhen Lin;Yan Li;Fuda Yu ;Zhaoyuan Qiu
ChemPhysChem 2013 Volume 14( Issue 2) pp:394-399
Publication Date(Web):
DOI:10.1002/cphc.201200816
Abstract
In order to achieve pesudocapacitive performance of single-wall carbon nanotube (SWCNT) electrodes, a high-efficient and reversible redox strategy utilizing a redox-mediated electrolyte for SWCNT-based supercapacitors is reported. In this novel redox-mediated electrolyte, the single-electrode specific capacitance of the supercapacitor is heightened four times, reaching C=162.66 F g−1 at 1 A g−1. The quick charge-discharge ability of the supercapacitor is also enhanced, and the relaxation time is as low as 0.58 s. Furthermore, the supercapacitor shows an excellent cycling performance of 96.51 % retention after 4000 cycles. The remarkable results presented here illustrate that the redox strategy is a facile and straightforward approach to improve the performances of SWCNT electrodes.
Co-reporter:LeQing Fan;Yuan Chen;JiHuai Wu;ZhaoLei Li;YaoMing Xiao
Science China Chemistry 2013 Volume 56( Issue 10) pp:1470-1477
Publication Date(Web):2013 October
DOI:10.1007/s11426-013-4937-2
Mesoporous TiO2 microsphere (MTM) was synthesized via a simple solution route and then mixed with commercial TiO2 (P25) to form highly homogeneous and stable TiO2 colloid by simple hydrothermal treatment. The TiO2 colloid was coated onto the plastic conductive substrate to prepare mesoporous TiO2 film for flexible dye-sensitized solar cells (DSSCs) by low-temperature heat treatment. The influence of MTM content on the physicochemical properties of the flexible TiO2 film was characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectrometer, N2 adsorption-desorption isotherms, UV-vis absorption and diffuse reflectance spectra. It is revealed that with increasing the MTM content, the dye-loading capability of TiO2 film and light-harvesting efficiency of flexible DSSCs are improved due to MTM having high surface area and acting as a light scattering center, respectively, resulting in the enhancement of photocurrent of flexible DSSCs. However, more and larger cracks having negative effect on the performances of flexible DSSCs are formed simultaneously. Under the optimal condition with MTM content of 20%, a flexible DSSC with overall light-to-electric energy conversion efficiency of 2.74% is achieved under a simulated solar light irradiation of 100 mW cm−2 (AM 1.5), with 26% improvement in comparison with DSSCs based on P25 alone.
Co-reporter:GenTian Yue;JiHuai Wu;YaoMing Xiao;JianMing Lin
Science China Chemistry 2013 Volume 56( Issue 1) pp:93-100
Publication Date(Web):2013 January
DOI:10.1007/s11426-012-4700-0
A microporous platinum/fullerenes (Pt/C60) counter electrode was prepared by using a facile rapid thermal decomposition method, and the quantum-dot sensitized solar cell (QDSSC) of Pt/C60-TiO2-CdS-ZnS and Pt/C60-TiO2-CdTe-ZnS was fabrication. The technique forms a good contact between QDs and TiO2 films. The photovoltaic performances of the as-prepared cells were investigated. The QDSSCs with Pt/C60 counter electrode show high power conversion efficiency of 1.90% and 2.06%, respectively (under irradiation of a simulated solar light with an intensity of 100 mW cm−2), which is comparable to the one fabricated using conventional Pt electrode.
Co-reporter:Guanglu Shang, Jihuai Wu, Shen Tang, Lu Liu, and Xiaopei Zhang
The Journal of Physical Chemistry C 2013 117(9) pp: 4345-4350
Publication Date(Web):February 13, 2013
DOI:10.1021/jp309193n
Highly crystalline SnO2 nanorods with lengths of about 200 nm and diameters of 40–80 nm are synthesized by a hydrothermal method. Because of an efficient electron transport channel along the one-dimensional structure, a dye-sensitized solar cell (DSSC) based on the SnO2 nanorods shows a fast electron transport and a long electron lifetime, resulting in higher power conversion efficiency than the DSSC SnO2-based nanoparticles. To suppress charge recombination at SnO2 nanorods and electrolyte/dye interfaces, we modify SnO2 nanorod electrode with TiO2 compact layer and TiCl4 post-treatment, and the DSSC exhibits a power conversion efficiency of 4.67%.
Co-reporter:Jihuai Wu;Yaoming Xiao;Qunwei Tang;Gentian Yue;Jianming Lin;Miaoliang Huang;Yunfang Huang;Leqing Fan;Zhang Lan;Shu Yin;Tsugio Sato
Advanced Materials 2012 Volume 24( Issue 14) pp:1884-1888
Publication Date(Web):
DOI:10.1002/adma.201200003
Co-reporter:Jihuai Wu;Jiangli Wang;Jianming Lin;Zhang Lan;Qunwei Tang;Miaoliang Huang;Yunfang Huang;Leqing Fan;Qingbei Li ;Ziying Tang
Advanced Energy Materials 2012 Volume 2( Issue 1) pp:78-81
Publication Date(Web):
DOI:10.1002/aenm.201100531
Co-reporter:Zhang Lan, Jihuai Wu, Jianming Lin and Miaoliang Huang
Journal of Materials Chemistry A 2012 vol. 22(Issue 9) pp:3948-3954
Publication Date(Web):25 Jan 2012
DOI:10.1039/C2JM15019K
The thermal decomposition method is usually used for fabricating Pt counter electrodes for dye-sensitized solar cells (DSSCs). The limitation of the method is its little control over the Pt particle size, agglomeration of the Pt particles on the conductive substrate and poor uniformity of the Pt counter electrodes. Herein, homogeneously dispersed Pt particles on FTO conductive glasses were prepared with an improved thermal decomposition method through adding a small amount of polyvinyl pyrrolidone (PVP) in the Pt precursor solution. The different additional amounts of PVP in the Pt precursor solution could influence the morphologies of the Pt counter electrodes, which further influenced the catalytic activity of the Pt counter electrodes and the photovoltaic performance of DSSCs. An enhanced energy conversion efficiency of the DSSC of about 8.394% was obtained when the Pt counter electrode was prepared with the additional weight amount of PVP 3.5 times that of H2PtCl6·6H2O in the Pt precursor solution, obviously higher than the original 7.062% value of the DSSC with the Pt counter electrode prepared by the traditional unmodified thermal decomposition method on the same loaded low weight of 3.765 μg cm−2.
Co-reporter:Jihuai Wu, Haijun Yu, Leqing Fan, Genggeng Luo, Jianming Lin and Miaoliang Huang
Journal of Materials Chemistry A 2012 vol. 22(Issue 36) pp:19025-19030
Publication Date(Web):2012/08/02
DOI:10.1039/C2JM33856D
A redox intermedium p-phenylenediamine (PPD) with quick reversible faradaic processes is introduced into KOH electrolyte, referred to as pseudocapacitive effect occurring on the electrode/electrolyte surface. The KOH + PPD electrolyte as potential electrolyte for supercapacitors is investigated by UV-Vis spectroscopy and electrochemical methods. As expected, the supercapacitor with KOH + PPD electrolyte has a much higher electrode specific capacitance (605.225 F g−1) than the one with conventional KOH electrolyte (144.037 F g−1) at the same current density of 1 A g−1. Simultaneously, the supercapacitor with KOH + PPD electrolyte exhibits a much higher energy density (19.862 W h kg−1) than the supercapacitor with conventional KOH electrolyte (4.458 W h kg−1). Furthermore, the supercapacitor with KOH + PPD electrolyte shows superior charge–discharge stability. After 4000 cycles, its capacitive retention ratio is still as high as 94.530%.
Co-reporter:Guanglu Shang, Jihuai Wu, Shen Tang, Miaoliang Huang, Zhang Lan, Yan Li, Junchang Zhao and Xiaoping Zhang
Journal of Materials Chemistry A 2012 vol. 22(Issue 48) pp:25335-25339
Publication Date(Web):16 Oct 2012
DOI:10.1039/C2JM33897A
Three-dimensional hierarchical tin oxide microspheres (HM-SnO2) are successfully synthesized by hydrothermal treatment. The SnO2 microspheres with diameter of 1–4 μm are pure rutile phase and consist of nanosheets. The two-dimensional nanosheets ensure fast electron transport and slow charge carrier recombination. Due to their large particle size, the HM-SnO2 films can scatter light efficiently and enhance light harvesting. Because of the above advantages, a dye-sensitized solar cell (DSSC) based on the HM-SnO2 photoanode shows an energy conversion efficiency of 4.55%, which indicates a 12.6% improvement compared to the DSSC based on a current SnO2 nanoparticle photoanode prepared under the same conditions. Moreover, the photovoltaic performance of the DSSC can be improved by modifying the photoanode with a TiO2 blocking layer and TiCl4 post-treatment.
Co-reporter:Yaoming Xiao, Jeng-Yu Lin, Sheng-Yen Tai, Shu-Wei Chou, Gentian Yue and Jihuai Wu
Journal of Materials Chemistry A 2012 vol. 22(Issue 37) pp:19919-19925
Publication Date(Web):03 Aug 2012
DOI:10.1039/C2JM34425D
High performance poly(3,4-ethylenedioxythiophene) (PEDOT) nano-meadows were electropolymerized onto multi-wall carbon nanotube (MWCNT) as counter electrodes (CEs) for Pt-free dye-sensitized solar cells (DSCs) for the first time. This composite film was fabricated using an electrophoresis of MWCNTs onto a fluorinated tin oxide glass substrate and then subjected to PEDOT electropolymerization by using the pulse potentiostatic method. The surface of MWCNTs was wrapped with nano-meadows PEDOT thin film of ∼55 nm in thickness. The extensive cyclic voltammograms (CV) showed PEDOT/MWCNT CE with excellent electrocatalytic activity for I3− reduction. Moreover, the peak current densities of the PEDOT/MWCNT CE showed no sign of degradation after consecutive 200 CV tests, suggesting the great electrochemical stability of the PEDOT/MWCNT CE. The electrochemical impedance spectroscopy demonstrated that the PEDOT/MWCNT CE had the lowest charge-transfer resistance among all CEs tested in this study. The DSC assembled with the PEDOT/MWCNT composite CE demonstrated an enhanced photovoltaic conversion efficiency of 7.03% compared to that using conventional Pt CE (5.88%) under full sunlight illumination (100 mW cm−2, AM1.5 G) due to the intrinsic superior electrocatalytic activity of the nano-meadows PEDOT material, highly specific surface area and high electrical conductivity of the MWCNTs. Therefore, the PEDOT/MWCNT CE can be considered as a promising alternative CE for use in Pt-free DSCs.
Co-reporter:Qunwei Tang, Jihuai Wu, Ziying Tang, Yan Li and Jianming Lin
Journal of Materials Chemistry A 2012 vol. 22(Issue 31) pp:15836-15844
Publication Date(Web):17 May 2012
DOI:10.1039/C2JM32637J
The development of high-temperature proton exchange membranes (HTPEMs) operated over 120 °C under anhydrous conditions is pursued worldwide in order to solve some core problems of current PEM fuel cells based on Nafion (CO tolerance, improved kinetics, water management, etc.). In the current work, two classes of HTPEMs based on absorbing and doping of the protic ionic liquid, 1-methylimidazolium trifluoromethanesulfonate ([MIm][Tfo]), into a 3D framework of poly(acrylic acid)–poly(ethylene glycol) (PAA–PEG) superabsorbent are successfully synthesized. The resultant membranes show high proton conductivity, good thermal stability and excellent mechanical strength due to the unique absorption property and interpenetrated polymer network of PAA–PEG, and good conduction of [MIm][Tfo]. Proton conductivities as high as 40.4 and 19.4 mS cm−1 at 200 °C under anhydrous conditions are obtained in [MIm][Tfo] doped and absorbed PAA–PEG membranes, respectively. The long-term stability of the superabsorbent-based membranes at high-temperatures, in combination with simple preparation, low cost, scalable host and proton conductor, demonstrates the potential use of these materials in HTPEMs.
Co-reporter:Jihuai Wu, Gentian Yue, Yaoming Xiao, Miaoliang Huang, Jianming Lin, Leqing Fan, Zhang Lan, and Jeng-Yu Lin
ACS Applied Materials & Interfaces 2012 Volume 4(Issue 12) pp:6530
Publication Date(Web):November 26, 2012
DOI:10.1021/am301397e
The tungsten sulfide/multi-wall carbon nanotube (WS2/MWCNT) hybrid was prepared in the presence of glucose by the hydrothermal route. The hybrid materials were used as counter electrode in the dye-sensitized solar cell (DSSC). The results of cyclic voltammetry measurement and electrochemical impedance spectroscopy indicated that the glucose aided prepared (G-A) WS2/MWCNT electrode had low charge-transfer resistance (Rct) and high electrocatalytic activity for triiodide reduction. The excellent electrochemical properties for (G-A) WS2/MWCNT electrode is due to the synergistic effects of WS2 and MWCNTs, as well as amorphous carbon introduced by glucose. The DSSC based on the G-A WS2/MWCNT counter electrode achieved a high power conversion efficiency of 7.36%, which is comparable with the performance of the DSSC using Pt counter electrode (7.54%).Keywords: counter electrode; dye-sensitized solar cells; multi-wall carbon nanotubes; tungsten sulfide;
Co-reporter:Yaoming Xiao, Jihuai Wu, Gentian Yue, Jianming Lin, Miaoliang Huang, Leqing Fan, Zhang Lan
Journal of Power Sources 2012 Volume 208() pp:197-202
Publication Date(Web):15 June 2012
DOI:10.1016/j.jpowsour.2012.02.019
We report that NaOH hydrothermal treatment and HF post-treatment of the titanium mesh for the Pt/Ti counter electrode improved the efficiency of dye-sensitized solar cells. High performance platinum nanoparticles have been sprayed onto Ti meshes to form counter electrodes for use in large-area flexible DSSCs using a vacuum thermal decomposition method at low temperature (120 °C). The obtained Pt/Ti counter electrode shows low charge-transfer resistance (57.52 Ω cm2 with active area of 80 cm2) and high electrocatalytic activity for the I3−/I− redox reaction. The photovoltaic properties and resistances of Pt/Ti counter electrodes with different HF post-treatment times of the NaOH treated Ti meshes have been investigated. The efficiency of the large-area (80 cm2) flexible DSSC reaches 6.17% under irradiation with a natural light intensity of 55 mW cm−2 measured outdoors.Highlights► The surface treatment of the Ti mesh increases the void space of the Pt/Ti counter electrode. ► The HF post-treatment of the Ti mesh decreases the resistance of the Pt/Ti counter electrode. ► The Pt/Ti counter electrode shows high electrocatalytic activity and low resistance. ► The photoelectric efficiency of the large-area (80 cm2) flexible DSSC reaches 6.17%.
Co-reporter:Ziying Tang, Jihuai Wu, Qin Liu, Min Zheng, Qunwei Tang, Zhang Lan, Jianming Lin
Journal of Power Sources 2012 Volume 203() pp:282-287
Publication Date(Web):1 April 2012
DOI:10.1016/j.jpowsour.2011.11.039
A microporous hybrid polymer of poly(acrylic acid)/gelatin/polyaniline (PAA/Gel/PANI) is synthesized with a two-steps solution polymerization. Using this hybrid as polymer host, a gel-electrolyte with a high liquid absorbency of 16.45 (g g−1) and a high conductivity of 14.38 mS cm−1 is prepared, then a quasi-solid-state dye-sensitized solar cell (QS-DSSC) is assembled. The polymer host is characterized by scanning electron microscopy (SEM), the functional groups on the polymer are identified by Fourier transform infrared spectroscopy (FTIR) and the photovoltaic tests of the QS-DSSCs are carried out by measuring current–voltage (I–V) curves. The QS-DSSC with this hybrid gel-electrolyte achieves a light-to-electric energy conversion efficiency of 6.94%.Highlights► A microporous hybrid polymer of poly(acrylic acid)/gelatin/polyaniline is synthesized. ► A gel electrolyte with conductivity of 14.38 mS cm−1 is obtained based on the polymer. ► A quasi-solid-state dye-sensitized solar cell with the electrolyte shows 6.94% efficiency.
Co-reporter:Haijun Yu, Jihuai Wu, Leqing Fan, Youzhen Lin, Kaiqing Xu, Ziying Tang, Cunxi Cheng, Shen Tang, Jianming Lin, Miaoliang Huang, Zhang Lan
Journal of Power Sources 2012 Volume 198() pp:402-407
Publication Date(Web):15 January 2012
DOI:10.1016/j.jpowsour.2011.09.110
A supercapacitor based on a novel redox-mediated gel polymer electrolyte (PVA–H2SO4–P–benzenediol) and activated carbon electrodes is assembled. The electrochemical properties of the supercapacitor are evaluated by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy techniques. It is found that the supercapacitor exhibits large specific capacitance (474.29 F g−1), high energy density (11.31 W h kg−1), and excellent cyclical stability. The good performance for the supercapacitor is due to the capacity-storage mechanism combination of the electrical double layer capacitance and Faradaic pseudocapacitance by p-benzenediol/p-benzoquinone in the electrolyte.Highlights► A novel redox-mediated gel electrolyte was prepared by doping p-benzenediol. ► The new gel electrolyte has a high ionic conductivity of 34.8 mS cm−1. ► The supercapacitor with the electrolyte shows a high Cs of 474.29 F g−1. ► The energy density of the supercapacitor with the electrolyte reaches 11.31 W h kg−1.
Co-reporter:Haijun Yu, Qunwei Tang, Jihuai Wu, Youzhen Lin, Leqing Fan, Miaoliang Huang, Jianming Lin, Yan Li, Fuda Yu
Journal of Power Sources 2012 Volume 206() pp:463-468
Publication Date(Web):15 May 2012
DOI:10.1016/j.jpowsour.2012.01.116
A separator is prepared based on natural and flexible eggshell membrane (ESM) for supercapacitor application. Morphology observation shows that the ESM is consisted of hierarchically ordered macroporous network. With a high decomposition temperature (>220 °C), enough mechanical strength (σmax = 6.59 ± 0.48 MPa, ɛmax = 6.98 ± 0.31%, respectively), and low water uptake and swelling property (<10%), ESM could be a promising candidate for supercapacitor separator. As expected, the supercapacitor with ESM separator exhibits outstanding electrochemical performances, such as low resistance, quick charge–discharge ability (τ is 4.76 s), and good cyclic stability (92% retention after 10,000 cycles). However, the one with PE separator shows worse properties (high resistance, low specific capacitance, etc.). This research provides new insight into the preparation of natural, low-cost and high-performance separator for supercapacitor and other applications.Highlights► An eggshell membrane (ESM) is prepared for the separator in supercapacitor. ► The ESM possesses low swelling, good stability, and high mechanical strength. ► Supercapacitor with the ESM separator exhibits excellent electrochemical performance.
Co-reporter:Yaoming Xiao, Jihuai Wu, Gentian Yue, Jianming Lin, Miaoliang Huang, Zhang Lan, Leqing Fan
Electrochimica Acta 2012 Volume 85() pp:432-437
Publication Date(Web):15 December 2012
DOI:10.1016/j.electacta.2012.08.077
High performance poly (3,4-ethylenedioxythiophene) (PEDOT) arrays were electrodeposited onto titanium (Ti) meshes to form counter electrodes (CEs) for use in large-area flexible dye-sensitized solar cells (DSSCs). The PEDOT growth was controlled by different cyclic voltammetry parameters. The surface feature, resistance, and photovoltaic properties of the PEDOT/Ti CEs based on different electrodeposition conditions were investigated. The obtained PEDOT/Ti CE showed higher electrocatalytic activity for the I3−/I− redox reaction than that of the Pt/Ti CE. The light-to-electric energy conversion efficiency of the large-area (100 cm2) flexible DSSC based on the PEDOT/Ti CE reached 6.33%, and a maximum power output of 0.348 W was achieved, under irradiation with a natural light intensity of 55 mW cm−2 measured outdoors. Compared with other materials to prepare CEs, the PEDOT/Ti CE could be suitable for the large scale flexible DSSCs.Highlights► The PEDOT growth was controlled with different cyclic voltammetry parameters. ► The PEDOT with high surface area was electrodeposited on the Ti mesh. ► The PEDOT/Ti CE showed higher catalytic activity than that of the Pt/Ti CE. ► The large-area DSSC reached 348 mW power output and 6.33% efficiency under outdoors.
Co-reporter:Yao-Ming Xiao, Jeng-Yu Lin, Ji-Huai Wu, Sheng-Yen Tai, Gen-Tian Yue
Electrochimica Acta 2012 Volume 83() pp:221-226
Publication Date(Web):30 November 2012
DOI:10.1016/j.electacta.2012.07.113
High performance nano-meadows poly(3,4-ethylenedioxythiophene) (PEDOT) were electropolymerized onto the fluorinated tin oxide (FTO) substrates as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs) by using the pulse potentiostatic electropolymerization method. Various pulse parameters were studied to control the morphology of PEDOT films. After optimization, a PEDOT film with nano-meadows morphology can be obtained under 1.2 V pulse-on potential, 0.2 V pulse-reversal potential, 1 s pulse-on period, 0.5 s pulse-reversal period, and total 900 duration time. The extensive cyclic voltammograms (CV) showed the nano-meadows PEDOT CE with excellent electrocatalytic activity for I3− reduction. Moreover, the peak current densities of the nano-meadows PEDOT CE showed no sign of degradation after consecutive 300 CV tests, suggesting the great electrochemical stability of the PEDOT CE. The electrochemical impedance spectroscopy showed the pulsed PEDOT CE has the lowest charge-transfer resistance (RCT) of 1.27 Ω cm2 among all CEs tested in this study. Thus, the DSSC assembled with the pulsed PEDOT CE showed an enhanced photovoltaic conversion efficiency of 6.40% (compared to 5.75% for DSSCs with Pt CE) under full sunlight illumination (100 mW cm−2, AM1.5 G) due to its intrinsic superior electrocatalytic activity and high surface area from the nano-meadows morphology. Therefore, the pulsed PEDOT CE can be considered as a promising alternative CE for use in low-cost Pt-free DSSCs.Highlights► The nano-meadows PEDOT was prepared using pulse electropolymerization. ► The pulsed PEDOT CE showed the lowest RCT of 1.27 Ω cm2. ►The efficiency of the Pt-free DSSC reached 6.40% based on the pulsed PEDOT CE.
Co-reporter:Gentian Yue, Jihuai Wu, Yaoming Xiao, Jianming Lin, Miaoliang Huang, Zhang Lan, Leqing Fan
Electrochimica Acta 2012 Volume 85() pp:182-186
Publication Date(Web):15 December 2012
DOI:10.1016/j.electacta.2012.08.117
A heterojunction consisted of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and poly(3-hexylthiophene) (P3HT) was employed as hole transporter and light absorber assistant, a microporous platinum/fullerenes (Pt/C60) counter electrode was prepared by using a facile thermal decomposition method, and a polydimethyldiallyl ammonium–cadmium telluride [(PDDA)–CdTe] quantum dots photoanode was prepared by using chemical bath deposition method. Based on above components, a CdTe quantum dot-sensitized solar cell (QDSSC) was fabricated. The QDSSC shows a light-to-electric energy conversion efficiency of 3.40% under a simulated solar light irradiation with an intensity of 100 mW cm−2. The electrochemical and photovoltaic measurements indicate that microporous Pt/C60 film is better than Pt film as counter electrode material for the QDSSCs, and PCBM/P3HT is better than iodide/triiodide and sulfide/polysulfide as transferring medium for QDSSCs.Highlights► A CdTe QD-sensitized solar cell was fabricated by using PCBM/P3HT heterojunction. ► The QDSSC shows a light-to-electric energy conversion efficiency of 3.40%. ► Microporous Pt/C60 film is better than Pt film as counter electrode for the QDSSC. ► PCBM/P3HT is better than I−/I3− and S2−/Sx as transferring medium for the QDSSC.
Co-reporter:Gentian Yue, Jeng-Yu Lin, Sheng-Yen Tai, Yaoming Xiao, Jihuai Wu
Electrochimica Acta 2012 Volume 85() pp:162-168
Publication Date(Web):15 December 2012
DOI:10.1016/j.electacta.2012.08.040
In this study, a composite film of molybdenum sulfide (MoS2)/graphene flake was characterized as the counter electrode (CE) for Pt-free dye-sensitized solar cells (DSSCs). It was found that the enhanced electrocatalytic activity can be demonstrated when high-conductive graphene flake was introduced into MoS2 film. The cyclic voltammograms showed that the cathodic current density of MoS2/graphene CE was higher than those of MoS2, graphene and Pt CEs due to its lamellar structure. Additionally, MoS2/graphene CE exhibited a low charge-transfer resistance of 2.17 Ω cm2. After the optimization in the thickness of MoS2/graphene CE, the power conversion efficiency of the DSSC assembled with the optimized MoS2/graphene reached 5.98% under AM1.5 illumination of 100 mW cm−2, which is comparable to that based on the Pt CE.Highlights► MoS2/graphene flake composite was characterized as CE in Pt-free DSSCs. ► The MoS2/graphene flake CE showed the low Rct of 2.17 Ω cm2. ► The efficiency of the Pt-free DSSC reached 5.98% based on the MoS2/graphene flake CE.
Co-reporter:Ziying Tang, Jihuai Wu, Min Zheng, Qunwei Tang, Qin Liu, Jianming Lin and Jiangli Wang
RSC Advances 2012 vol. 2(Issue 10) pp:4062-4064
Publication Date(Web):06 Mar 2012
DOI:10.1039/C2RA20180A
A one-dimensional PANI nanofiber supported Pt nanoparticle film is prepared by a two-step electrochemical deposition method. The PANI/Pt film possesses high conductivity, surface area and catalytic activity. A dye-sensitized solar cell based on the PANI/Pt film achieves a high light-to-electric energy conversion efficiency of 7.69%.
Co-reporter:Ziying Tang, Qunwei Tang, Jihuai Wu, Yan Li, Qin Liu, Min Zheng, Yaoming Xiao, Gentian Yue, Miaoliang Huang and Jianming Lin
RSC Advances 2012 vol. 2(Issue 12) pp:5034-5037
Publication Date(Web):27 Mar 2012
DOI:10.1039/C2RA20194A
A large-scale hierarchical flower-like platinum counter electrode was successfully prepared by a template-free route. The platinum flower is composed of numerous of petal-like platinum nanosheets with a thickness of 25–30 nm, with a significantly enhanced active surface-area and electrochemical performance in DSSCs. The DSSC based on the flower-like Pt counter electrode shows an efficiency of 7.94%, which is enhanced by 19.2% compared to that of a conventional Pt nanoparticle electrode.
Co-reporter:Haijun Yu, Leqing Fan, Jihuai Wu, Youzhen Lin, Miaoliang Huang, Jianming Lin and Zhang Lan
RSC Advances 2012 vol. 2(Issue 17) pp:6736-6740
Publication Date(Web):13 Jun 2012
DOI:10.1039/C2RA20503C
A simple method has been implemented to prepare a stable and effective redox-active alkaline electrolyte by doping m-phenylenediamine into a conventional KOH electrolyte for a carbon-based supercapacitor. The quick electron transfer and reversible Faradic process in the new electrolyte system results in additional pseudocapacitive contribution for a carbon-based supercapacitor. The specific capacitance of the supercapacitor based on the new electrolyte is 78.01 F g−1, which is an increase of 114.16% over that of a supercapacitor based on a conventional KOH electrolyte (36.43 F g−1). Additionally, the supercapacitor exhibits an excellent cyclical stability.
Co-reporter:Yaoming Xiao, Jihuai Wu, Gentian Yue, Jianming Lin, Miaoliang Huang, Leqing Fan and Zhang Lan
RSC Advances 2012 vol. 2(Issue 28) pp:10550-10555
Publication Date(Web):06 Sep 2012
DOI:10.1039/C2RA21580B
Platinum (Pt) and single-wall carbon nanotubes (SWCNTs) were sprayed onto Titanium (Ti) mesh to form a Pt–SWCNT/Ti counter electrode using a vacuum thermal decomposition method at a low temperature. A three-dimensional interpenetrating network of TiO2 nanowires (3-D IPN TNWs) was successfully prepared on Ti foil through a facile hydrothermal approach. A TiO2 colloid was coated on the 3-D IPN TNWs to form a large-area flexible anode using a doctor-scraping technique. The influences of the concentration of NaOH on the growth of 3-D IPN TNWs and on the photovoltaic performances of dye-sensitized solar cells (DSSCs) were investigated. Under an optimized condition, the power conversion efficiency of a large-area (100 cm2) flexible DSSC reached 6.43%, with a short-circuit current density of 6.83 mA cm−2, an open circuit voltage of 0.724 V, and a fill factor of 0.715. Under irradiation with a natural light intensity of 55 mW cm−2 outdoors, the efficiency of power conversion was increased by 10.29% compared with the flexible DSSC without 3-D IPN TNWs.
Co-reporter:Qunwei Tang, Lin Lin, Zhengping Mao, Ziying Tang and Jihuai Wu
RSC Advances 2012 vol. 2(Issue 6) pp:2211-2216
Publication Date(Web):01 Feb 2012
DOI:10.1039/C2RA00889K
Hierarchical ZnO microrods were successfully grown on the upward surface of a Si substrate by a low-temperature hydrothermal method. The morphology and size can be easily controlled by adjusting reaction temperature and reactant concentration. The photocatalytic activities were evaluated by the degradation of Rhodamine B (RB) dye under UV and visible irradiation. The resultant hierarchical ZnO microrods show better photocatalytic activities for the photodegradation of RB than traditional nanoparticles and aligned nanorods.
Co-reporter:Jiangli Wang; Jihuai Wu; Jianming Lin; Miaoliang Huang;Dr. Yunfang Huang;Dr. Zhang Lan;Dr. Yaoming Xiao;Dr. Gentian Yue;Dr. Shu Yin; Tsugio Sato
ChemSusChem 2012 Volume 5( Issue 7) pp:1307-1312
Publication Date(Web):
DOI:10.1002/cssc.201100596
Abstract
Y2O3:Er3+ nanorods are synthesized by means of a hydrothermal method and then introduced into a TiO2 electrode in a dye-sensitized solar cell (DSSC). Y2O3:Er3+ improves infrared light harvest via up-conversion luminescence and increases the photocurrent of the DSSC. The rare earth ions improve the energy level of the TiO2 electrode through a doping effect and thus increase the photovoltage. The light scattering is ameliorated by the one-dimensional nanorod structure. The DSSC containing Y2O3:Er3+ (5 wt %) in the doping layer achieves a light-to-electric energy conversion efficiency of 7.0 %, which is an increase of 19.9 % compared to the DSSC lacking of Y2O3:Er3+.
Co-reporter:Qunwei Tang, Lin Lin, Xuan Zhao, Kevin Huang, and Jihuai Wu
Langmuir 2012 Volume 28(Issue 8) pp:3972-3978
Publication Date(Web):February 4, 2012
DOI:10.1021/la204522v
Recently, there has been growing interest in the design of novel nano- and/or microscaled heterojunctions consisting of two distinctive ordered semiconductor arrays for highly efficient p–n diodes used in optical, optielectronic, and microelectronic devices. Here, we report the attainment of an ordered double array comprising of p-type polyaniline microrods and n-type ZnO nanowires by a controlled electrochemical deposition method. Extensive chemical and physical characterizations have been performed on the fabricated p–n heterojunction. The double-array p–n heterojunction exhibits good rectifying characteristics, the rectification ratio of which exhibits a minimum at an illumination density of 93 mW cm–2, making it suitable for high-sensitivity photodetectors. This research is expected to open up a new avenue for the development of highly efficient and sensitive p–n heterojunction diodes and possibly serve as the building blocks for future nanoelectronics.
Co-reporter:Gentian Yue, Jihuai Wu, Yaoming Xiao, Jianming Lin, Miaoliang Huang, and Zhang Lan
The Journal of Physical Chemistry C 2012 Volume 116(Issue 34) pp:18057-18063
Publication Date(Web):August 2, 2012
DOI:10.1021/jp303958r
A low-cost poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) and polypyrrole (PPy) composite film was fabricated on a rigid fluorine-doped tin oxide (FTO) substrate used as the counter electrode in a dye-sensitized solar cell (DSSC) by a facile electrochemical polymerization method. The cyclic voltammetry and electrochemical impedance spectroscopy measurements show that the PEDOT:PSS/PPy film has a low surface resistance, high conductivity, and good catalytic performance for the I–/I3– electrolyte. The power conversion efficiency of the DSSC based on the PEDOT:PSS/PPy counter electrode reaches 7.60% under a simulated solar light illumination of 100 mW·cm–2; the efficiency is comparable to that of the DSSCs based on a sputtered Pt electrode.
Co-reporter:Zhang Lan, Jihuai Wu, Jianming Lin, Miaoliang Huang
Electrochimica Acta 2012 60() pp: 17-22
Publication Date(Web):
DOI:10.1016/j.electacta.2011.10.075
Co-reporter:Zhang Lan;JiHuai Wu;JianMing Lin;MiaoLiang Huang
Science China Chemistry 2012 Volume 55( Issue 7) pp:1308-1313
Publication Date(Web):2012 July
DOI:10.1007/s11426-012-4638-2
A simple method for the controllable hydrothermal synthesis of nanocrystalline anatase TiO2 (nc-TiO2) particles involving the selection of suitable organic alkali peptizing agents is reported. A dye-sensitized solar cell (DSSC) with square-like nc-TiO2 particles with side lengths about 8–13 nm—prepared using tetraethylammonium hydroxide (TEAOH)—in the photoelectrode showed higher photovoltaic performance than two other DSSCs with square-like nc-TiO2 particles with side lengths about 7–10 nm—prepared using tetrabutylammonium hydroxide—or elongated nc-TiO2 particles with lengths about 18–35 nm and width about 10–18 nm—prepared using tetramethylammonium hydroxide (TMAOH)—in the photoelectrodes. When a scattering layer prepared from sub-micron size spheres or cone-like nc-TiO2 particles—synthesized using a higher concentration of TMAOH—was added on top of the photoelectrode fabricated from nc-TiO2 synthesized with TEAOH, the energy conversion efficiency of the DSSC was markedly increased from 6.77% to 8.18%.
Co-reporter:HaiJun Yu;JiHuai Wu;LeQing Fan;YouZhen Lin;ShuHong Chen
Science China Chemistry 2012 Volume 55( Issue 7) pp:1319-1324
Publication Date(Web):2012 July
DOI:10.1007/s11426-012-4673-z
This paper reports a novel strategy for preparing redox-active electrolyte through introducing a redox-mediator (p-phenylenediamine, PPD) into KOH electrolyte for the application of ball-milled MnO2-based supercapacitors. The morphology and compositions of ball-milled MnO2 were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical properties of the supercapacitor were evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. The introduction of p-phenylenediamine significantly improves the performance of the supercapacitor. The electrode specific capacitance of the supercapacitor is 325.24 F g−1, increased by 6.25 folds compared with that of the unmodified system (44.87 F g−1) at the same current density, and the energy density has nearly a 10-fold increase, reaching 10.12 Wh Kg−1. In addition, the supercapacitor exhibits good cycle-life stability.
Co-reporter:Zhang Lan;JiHuai Wu;JianMing Lin;MiaoLiang Huang
Science China Chemistry 2012 Volume 55( Issue 2) pp:242-246
Publication Date(Web):2012 February
DOI:10.1007/s11426-011-4393-9
A new kind of gel electrolyte containing only organic solvents and an iodide salt—namely 3-methoxypropionitrile (MPN), aniline and AlI3—has been prepared. Gel formation results from the Lewis acid-base interaction between the Lewis acid ionic conductor AlI3 and the Lewis base organic solvent aniline and no additional gelling agent is required. The AlI3-aniline complex acts both as an ionic conductor and as a gelling agent. The differences between the peaks characteristic of the —NH2 group and aromatic ring in the FTIR spectra of free aniline and the AlI3-aniline hybrid confirm the formation of the AlI3-aniline complex. The photovoltaic performance and long-term stability of dye-sensitized solar cells can be greatly enhanced by the addition of aniline to the AlI3-MPN liquid electrolyte.
Co-reporter:Cunxi Cheng;Jihuai Wu;Yaoming Xiao;Yuan Chen;Haijun Yu
Frontiers of Optoelectronics 2012 Volume 5( Issue 2) pp:224-230
Publication Date(Web):2012 June
DOI:10.1007/s12200-012-0198-5
Titanium dioxide-double-walled carbon nanotubes (TiO2-DWCNTs) with DWCNTs/TiO2 of 20 wt.% is prepared by a conventional sol-gel method. Doping the TiO2-DWCNTs in TiO2 photoanode, a flexible dye-sensitized solar cell (DSSC) is fabricated. The sample is characterized by scanning electron microscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) absorption, ultraviolet-visible spectroscopy (UVvis) absorption spectra, electrochemical impedance spectroscopy (EIS) technique and photovoltaic measurement. It is found that adding a certain amount of TiO2-DWCNTs can efficiently decrease the resistance of charge transport, improve dye adsorption. Under an optimal condition, a flexible DSSC contained with 0.50 wt.% TiO2-DWCNTs achieves a light-to-electric energy conversion efficiency of 3.89% under a simulate solar light irradiation of 100mW·cm−2.
Co-reporter:Sancun Hao, Jihuai Wu, Zhonglin Sun
Thin Solid Films 2012 Volume 520(Issue 6) pp:2102-2105
Publication Date(Web):1 January 2012
DOI:10.1016/j.tsf.2011.08.061
Hydrogenated amorphous silicon film (a-Si:H) as top cell is introduced to dye-sensitized titanium dioxide nanocrystalline solar cell (DSSC) as bottom cell to assemble a hybrid tandem solar cell. The hybrid tandem solar cell fabricated with the thicknesses a-Si:H layer of 235 nm, ZnO/Pt interlayer of 100 nm and DSSC layer of 8.5 μm achieves a photo-to-electric energy conversion efficiency of 8.31%, a short circuit current density of 10.61 mA·cm− 2 and an open-circuit voltage of 1.45 V under a simulated solar light irradiation of 100 mW·cm− 2.
Co-reporter:Zhang Lan, Jihuai Wu, Jianming Lin, Miaoliang Huang, Xiaoxi Wang
Thin Solid Films 2012 Volume 522() pp:425-429
Publication Date(Web):1 November 2012
DOI:10.1016/j.tsf.2012.08.017
This article presents the fabrication of a homogeneous mirror-like Pt-counter electrodes and its utilization in dye-sensitized solar cells (DSSCs). The homogeneous Pt-counter electrodes were fabricated through modified thermal decomposition method by adding a suitable amount of polyvinyl pyrrolidone (PVP) in a high concentration of Pt precursor solution. The micro-morphology of prepared Pt-counter electrodes was compared with those prepared by traditional thermal decomposition and electrochemical deposition methods. The different preparation methods showed obvious influence on the micro-morphologies of Pt-counter electrodes, which further influence the catalytic activity for iodide/tri-iodide redox reaction and hence the photovoltaic performance of DSSCs. A remarkable enhancement in the photovoltaic performance of the DSSCs was achieved by the application of the prepared Pt-counter electrodes through the modified thermal decomposition method. Moreover, an obvious improvement in the reflectance properties of the prepared Pt-counter electrodes was observed, which plays an important contribution in the enhancement of the photovoltaic performance of the DSSCs.Highlights► Pt mirror counter electrodes were prepared for dye-sensitized solar cells (DSSCs). ► The catalytic activity was influenced by the micro-morphology of Pt counter electrode. ► An improved DSSC performance was obtained with high reflectance Pt counter electrode.
Co-reporter:Qunwei Tang, Yan Li, Ziying Tang, Jihuai Wu, Jianming Lin and Miaoliang Huang
Journal of Materials Chemistry A 2011 vol. 21(Issue 40) pp:16010-16017
Publication Date(Web):13 Sep 2011
DOI:10.1039/C1JM12952J
To elevate the operating temperature of proton exchange membranes (PEMs) to 200 °C under anhydrous conditions, in the current work, the protic ionic liquid, 1-methylimidazolium trifluoromethanesulfonate ([MIm][Tfo]), was used as an anhydrous proton conductor and integrated with a superabsorbent host polyacrylamide/polyethylene glycol interpenetrated polymer network (PAM/PEG IPN) by doping and adsorbing methods. The resultant membranes could be operated up to 200 °C under nonhumidified conditions, showing a proton conductivity of 17.02 and 10.37 mS cm−1 at 150 °C for [MIm][Tfo] doped and adsorbed PAM/PEG IPN membranes, respectively. Because of the intrinsic nature of the PAM/PEG IPN superabsorbent, the loaded [MIm][Tfo] could not leak from the PEM systems even under high temperatures and pressures. A percolation phenomenon was observed because of the formation of proton-conducting channels for proton transfer. The new PEM presented a maximum tensile strength of 12.4 MPa and elongation of 1068% and 10.0 MPa and 1594% for the membranes by doping and adsorbing methods, respectively. To increase the electrocatalytic activity and decrease the cost of the catalyst, we also developed a well-aligned low-Pt anode catalyst using a fir template, exhibiting high activity for methanol oxidation reaction. When the methanol gas was bubbled into [MIm][Tfo] around the anode catalyst parallel to its channels, the oxidation current density at 200 °C was 8.7 times larger than that at 25 °C, whereas it was 5.4 times larger at 200 °C than that at 25 °C perpendicular to its channels. The membranes and efficient catalysts are possible candidates for direct methanol fuel cells that operate at high temperature and anhydrous conditions. The use of superabsorbents opens up a new route to high-temperature PEMs.
Co-reporter:Qunwei Tang, Jihuai Wu, Ziying Tang, Yan Li, Jianming Lin and Miaoliang Huang
Journal of Materials Chemistry A 2011 vol. 21(Issue 35) pp:13354-13364
Publication Date(Web):03 Aug 2011
DOI:10.1039/C1JM11857A
Flexible and uniquely network-structured polyaniline (PANi) and polypyrrole (PPy) supported Pt and Ag catalysts were synthesized using eggshell membrane as a template and explored for the methanol oxidation reaction (MOR) for proton exchange membrane fuel cell (PEMFC) application. The scanning electron microscopy observation showed a hierarchically ordered macroporous network of PANi and PPy. Due to the difference of polymer and metal essences, Pt was in the form of nanoparticles and Ag was in the form of nanofibers on the surfaces of PANi and nanoflakes on PPy. Energy dispersive X-ray spectra, thermal gravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction patterns and X-ray photoelectron spectra were used to characterize the resultant catalysts. The results revealed that the prepared flexible catalysts had a Pt loading of 7.5 and 7.48 wt% in Pt/PANi and Pt/PPy, and a Ag loading of 11.3 and 5.78 wt% in Ag/PANi and Ag/PPy, respectively. The PANi network was in its crystalline structure, which was expected to provide very high conductivities and electrochemical properties. The cyclic voltammetric studies at room temperature showed an excellent electrocatalytic activity for MOR in acidic medium. The catalysts were also checked in the electro-oxidation of methanol at high temperatures, a much higher electrocatalytic activity at 200 °C than that at 50 °C and good stability made them potential candidates for high-temperature PEMFCs. Combined with the mechanical strength, it is believed that PANi-based catalysts are more useful in MOR applications. The excellent properties, alterable supports, simple preparation procedure and low cost allow these catalysts to be used in high-temperature PEMFCs and other fields.
Co-reporter:Qunwei Tang, Jihuai Wu, Yan Li, Jianming Lin, Ziying Tang and Miaoliang Huang
Journal of Materials Chemistry A 2011 vol. 21(Issue 34) pp:12927-12934
Publication Date(Web):28 Jul 2011
DOI:10.1039/C1JM12037A
Polyaniline (PANi) microtube arrays were synthesized by a secondary-template (fir wood and ZnO microtube array) method and confirmed by scanning electron microscopy (SEM). High magnification SEM observation revealed that the PANi microtube arrays were formed by nanospheres and nanorods. X-Ray diffraction, Fourier transform infrared spectroscopy and cyclic voltammetry were used to characterize the resultant PANi microtube arrays which were subsequently used as electrodes for glucose oxidase (GO) immobilization and the detection of glucose. Compared with the traditional PANi powder electrode, the bioelectrocatalytic activation of GO immobilized PANi microtube array electrode toward the oxidation of glucose has been significantly enhanced. The excellent properties, low cost, facile preparation and good biocompatibility of the PANi microtube arrays set a bridge between proteins/enzymes and electrodes, providing analytical access to a large group of enzymes for a variety of biosensor applications.
Co-reporter:Qunwei Tang, Ziying Tang, Jihuai Wu, Jianming Lin and Ilkwon Oh
Journal of Materials Chemistry A 2011 vol. 21(Issue 14) pp:5378-5385
Publication Date(Web):24 Feb 2011
DOI:10.1039/C0JM04055J
This article reports a simple, versatile approach to the fabrication of high conducting multilayer films composed of alternating graphene (G) nanosheets and poly(sodium 4-styrenesulfonate) (PSS) using an electrostatic spin self-assembly technique. G nanosheets were prepared from natural graphite by oxidization, expansion, exfoliation, reduction and modification with cationic surfactant cetyltrimethylammonium bromide (C16TAB) and anionic surfactant sodium dodecyl sulfate (SDS). The growth process of the (PSS/G+/G−)n multilayer films was characterized by UV-vis spectroscopy. Absorbance plotted against the number of bilayers exhibited a linear dependence, indicating a progressive and uniform deposition process of the multilayer films. Higher rotation speeds (ω) can be used to fabricate thinner films, and the G content is in direct proportion to ω−1/2. The prepared (PSS/G+/G−)n multilayer films exhibit an attractive electrical conductivity in the range of 80–110 S cm−1. When the film thickness overcomes the effect of surface roughness and film morphology, a percolation effect is observed at the percolation threshold. The effects of the number of bilayers on the electrical properties of the ultrathin films are investigated in detail. The results show that the conductivity and percolation threshold can be controlled by adjusting the PSS/G+/G− ratio, rotation speed, and size of G nanosheets.
Co-reporter:Fuguo Peng, Jihuai Wu, Qingbei Li, Yue Wang, Gentian Yue, Yaoming Xiao, Qinghua Li, Zhang Lan, Leqing Fan, Jianming Lin, Miaoliang Huang
Electrochimica Acta 2011 Volume 56(Issue 14) pp:5184-5188
Publication Date(Web):30 May 2011
DOI:10.1016/j.electacta.2011.03.045
Co-reporter:Cunxi Cheng, Jihuai Wu, Yaoming Xiao, Yuan Chen, Leqing Fan, Miaoliang Huang, Jianming Ling, Jiangli Wang, Ziying Tang, Gengtian Yue
Electrochimica Acta 2011 Volume 56(Issue 21) pp:7256-7260
Publication Date(Web):30 August 2011
DOI:10.1016/j.electacta.2011.06.057
Polyvinyl pyrrolidone (PVP) is introduced to low temperature preparation of a good quality TiO2 film used in flexible dye-sensitized solar cells (DSSCs). The samples are characterized by scanning electron microscopy and UV–vis absorption spectra, the photovoltaic performance of the DSSC is measured. It is found that PVP can improve the dispersion of TiO2 particles and the adherence of TiO2 particles to flexible substrate, as well as the adsorption of sensitized dye to TiO2 film. Additionally, ultraviolet light irradiation can eliminate organics remained on the surface the TiO2 film and improve the surface state of TiO2 film. Under an optimal condition, a flexible DSSC using TiO2 film doped PVP and UV irradiation treated achieves a light-to-electric energy conversion efficiency of 3.02% under irradiation with a simulate solar light intensity of 100 mW cm−2.Highlights• Polyvinyl pyrrolidone (PVP) is used to low temperature prepare TiO2 film in flexible DSSC. • PVP improves TiO2 dispersion, adherence to flexible substrate and dye adsorption. • Ultraviolet light irradiation improve the surface state of TiO2 film. • Resultant flexible DSSC achieves a light-to-electric conversion efficiency of 3.02%.
Co-reporter:Yaoming Xiao, Jihuai Wu, Gentian Yue, Jianmin Lin, Miaoliang Huang, Zhang Lan
Electrochimica Acta 2011 Volume 56(Issue 24) pp:8545-8550
Publication Date(Web):1 October 2011
DOI:10.1016/j.electacta.2011.07.043
A platinum/single-wall carbon nanotube (Pt/SWCNT) film was sprayed onto a flexible indium-doped tin oxide coated polyethylene naphthalate (ITO/PEN) substrate to form a counter electrode for use in a flexible dye-sensitized solar cell using a vacuum thermal decomposition method at low temperature (120 °C). The obtained Pt/SWCNT electrode showed good chemical stability and light transmittance and had lower charge transfer resistance and higher electrocatalytic activity for the I3−/I− redox reaction compared to the flexible Pt electrode or a commercial Pt/Ti electrode. The light-to-electric energy conversion efficiency of the flexible DSSC based on the Pt/SWCNT/ITO/PEN counter electrode and the TiO2/Ti photoanode reached 5.96% under irradiation with a simulated solar light intensity of 100 mW cm−2. The efficiency was increased by 25.74% compared to the flexible DSSC with an unmodified Pt counter electrode.Highlights► A flexible Pt/SWCNT electrode was prepared by a vacuum thermal decomposition at 120°C. ► The electrode has lower resistance and higher electrocatalytic activity than Pt. ► The photoelectric efficiency of flexible cell with Pt/SWCNT electrode reaches 5.96%. ► The efficiency is increased by 25.74% compared to the cell with current Pt electrode.
Co-reporter:Yaoming Xiao, Jihuai Wu, Gentian Yue, Jianming Lin, Miaoliang Huang, Leqing Fan, Zhang Lan
Electrochimica Acta 2011 Volume 58() pp:621-627
Publication Date(Web):30 December 2011
DOI:10.1016/j.electacta.2011.10.008
Co-reporter:Ziying Tang, Qin Liu, Qunwei Tang, Jihuai Wu, Jiangli Wang, Shuhong Chen, Cunxi Cheng, Haijun Yu, Zhang Lan, Jianming Lin, Miaoliang Huang
Electrochimica Acta 2011 Volume 58() pp:52-57
Publication Date(Web):30 December 2011
DOI:10.1016/j.electacta.2011.08.074
A microporous hybrid polymer of poly(acrylic acid)-g-cetyltrimethylammonium bromide/polyaniline (PAA-g-CTAB/PANI) was synthesized by a two-steps solution polymerization. Using this amphipathic hybrid as host, a gel-electrolyte with a high absorbency of 17.69 (g/g) and a high conductivity of 14.29 mS cm−1 was prepared. The polymer hosts have been characterized by means of scanning electron microscopy (SEM), and the microporous network structure was observed. Fourier transform infrared spectroscopy (FTIR) and the electrochemical property tests of the gel-electrolytes have been carried out by means of I–V measurements. The quasi-solid-state dye-sensitized solar cells (QS-DSSCs) based on the hybrid gel-electrolyte reach a light-to-current efficiency of 6.68%.Highlights► A gel-electrolyte is prepared by introducing PANI into PAA-g-CTAB polymer network. ► The quasi-solid-state electrolyte shows a high conductivity of 14.29 mS cm−1. ► The DSSC with the electrolyte achieves an energy conversion efficiency of 6.68%.
Co-reporter:Haijun Yu, Jihuai Wu, Leqing Fan, Kaiqing Xu, Xin Zhong, Youzhen Lin, Jianming Lin
Electrochimica Acta 2011 Volume 56(Issue 20) pp:6881-6886
Publication Date(Web):1 August 2011
DOI:10.1016/j.electacta.2011.06.039
A quasi-solid-state supercapacitor was assembled by using alkaline polyvinyl alcohol and potassium iodide (PVA–KOH–KI) as gel electrolyte and activated carbons electrodes. The electrocapacitive properties of the supercapacitor were evaluated by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy techniques. The introduction of KI increases the ionic conductivity of electrolyte, and improves the pseudocapacitance of the electrode. The specific capacitances of the supercapacitor is 236.90 F g−1, increasing by 74.28% compared to the PVA–KOH system at the same current density. The energy density and power density of the supercapacitor reach 7.80 Wh kg−1 and 15.34 kW kg−1, respectively. In addition, the supercapacitor exhibits excellent cycle-life stability.Highlights► A quasi-solid-state polymer gel electrolyte was prepared by introducing KI into PVA–KOH system. ► The KI enhances the ionic conductivity, pseudocapacitance and performance of supercapacitor. ► The PVA–KOH–KI and PVA–KOH electrolytes has conductivity of 12.73 and 5.55 mS cm−1, respectively. ► The supercapacitor has a capacitance of 237 F g−1, increasing by 74% compared to the PVA–KOH system.
Co-reporter:Zhang Lan, Jihuai Wu, Jianming Lin, Miaoliang Huang
Electrochimica Acta 2011 Volume 56(Issue 27) pp:9926-9930
Publication Date(Web):30 November 2011
DOI:10.1016/j.electacta.2011.08.073
A bi-functional nanocrystalline TiO2 (nc-TiO2) layer able to offer both light-scattering and electron generating properties was prepared with a simple method through adding the basic NH3·H2O agent into an acid nc-TiO2 paste to form some big rod-like nc-TiO2 aggregates by the chemical sintering process. The influence of additional amount of NH3·H2O on the photovoltaic performance of the dye-sensitized solar cell with this bi-functional nc-TiO2 layer in the photoelectrode was studied. It was found that through controlling the additional amount of NH3·H2O and the thickness of the bi-functional nc-TiO2 layer, the highest energy conversion efficiency about 8.11% could be obtained, which was much higher than that of the dye-sensitized solar cell containing a single nc-TiO2 layer prepared with the original acid nc-TiO2 paste (4.34%).Graphical abstractChemical sintered bi-functional nanocrystalline TiO2 layers for highly efficient photoelectrodes.Highlights► A chemical sintered bi-functional nanocrystalline TiO2 layer was prepared. ► The nanocrystalline TiO2 layer can offer both light-scattering and electron generating properties. ► The DSSC with this nanocrystalline TiO2 layer in the photoelectrode shows obviously enhanced photovoltaic performance. ► The influence of additional amount of NH3·H2O chemical sintering agent on the photovoltaic performance of DSSCs was studied.
Co-reporter:Qingbei Li, Jianming Lin, Jihuai Wu, Zhang Lan, Yue Wang, Fuguo Peng, Miaoliang Huang
Electrochimica Acta 2011 Volume 56(Issue 14) pp:4980-4984
Publication Date(Web):30 May 2011
DOI:10.1016/j.electacta.2011.03.125
In order to increase of the photocurrent, photovoltage and energy conversion efficiency of dye-sensitized solar cell (DSSC), rare-earth doped oxide of Lu2O3:(Tm3+, Yb3+) is prepared and introduced into the TiO2 film in the DSSC. As a luminescence medium, Lu2O3:(Tm3+, Yb3+) improves incident light harvest via a conversion luminescence process and increases photocurrent; as a p-type dopant, the rare-earth ions elevate the energy level of the oxide film and increase the photovoltage. Under a simulated solar light irradiation of 100 mW cm−2, the light-to-electric energy conversion efficiency of the DSSC with Lu2O3:(Tm3+, Yb3+) doping reaches 6.63%, which is increased by 11.1% compared to the DSSC without Lu2O3:(Tm3+, Yb3+) doping.Highlights► Tm3+/Yb3+ codoped oxide is introduced into the TiO2 film in dye-sensitized solar cell. ► The RE improves light harvest via conversion luminescence and increases photocurrent. ► The RE elevates the oxide film energy level and increases the cell photovoltage. ► The cell efficiency is increased by 11.1% compared to the cell lacking of RE doping.
Co-reporter:Qunwei Tang, Ziying Tang, Jihuai Wu, Jianming Lin and Miaoliang Huang
RSC Advances 2011 vol. 1(Issue 8) pp:1453-1456
Publication Date(Web):11 Oct 2011
DOI:10.1039/C1RA00712B
A macroporous silver network was facilely synthesized using eggshell membrane as template and explored for methanol oxidation reaction, showing a significantly enhanced electrocatalytic ability compared with a traditional silver mirror electrode. The scanning electron microscopy observation showed a hierarchically ordered macroporous silver network because of the Ag+-protein binding. Energy dispersive X-ray spectrum, X-ray diffraction patterns and X-ray photoelectron spectra were used to characterize the resultant macroporous Ag network. The cyclic voltammetric studies at room temperature showed an excellent electrocatalytic activity for a methanol oxidation reaction in an acidic medium. The macroporous silver network was also checked in the electro-oxidation of methanol at high temperatures. A much higher electrocatalytic activity at 250 °C than that at 50 °C made them potential candidates for high-temperature proton exchange membrane fuel cells. The research opens a new insight to design low-cost, highly active and stable catalysts for methanol oxidation. The facile synthesis, excellent properties, alterable supports and low cost allow this material to be used in high-temperature direct methanol fuel cells.
Co-reporter:Zhang Lan;Jihuai Wu;Jianming Lin ;Miaoliang Huang
Polymers for Advanced Technologies 2011 Volume 22( Issue 12) pp:1812-1815
Publication Date(Web):
DOI:10.1002/pat.1675
Abstract
Quasi-solid state dye-sensitized solar cells (QS-DSSC) containing poly (methyl methacrylate-co-acrylonitrile) [P (MMA-co-AN)] gel electrolytes were fabricated. By tuning AN molar percentage in P (MMA-co-AN), the optimized polymeric gel electrolyte for fabricating QS-DSSC can be obtained. QS-DSSC containing polymeric gel electrolyte with 45 mol.% AN in P(MMA-co-AN) shows higher energy conversion efficiency than that of QS-DSSCs containing polymeric gel electrolytes with either pure PMMA or PAN. So it presents an effective way to improve the photovoltaic performance of QS-DSSC by tuning the components of polymeric gelling agent. Copyright © 2010 John Wiley & Sons, Ltd.
Co-reporter:Zhang Lan;Jihuai Wu;Jianming Lin ;Miaoliang Huang
Journal of Applied Polymer Science 2011 Volume 120( Issue 5) pp:2786-2789
Publication Date(Web):
DOI:10.1002/app.33183
Abstract
Oligomer ethylene glycol (O-EG) based electrolytes without volatile components were prepared and used in dye-sensitized solar cell (DSSC). The characteristics such as viscosity, ionic conductivity, and ionic activation energy of O-EG based electrolytes including liquid, gel and solid states were investigated and compared. It is found that the gel and solid O-EG electrolytes have two Ea values with the changed phase state by going with the increased temperature, and they can increase the onset of applied voltage for generating dark current in DSSCs as from 0.222 V with liquid O-EG electrolyte to 0.420 V with gel and solid O-EG electrolytes, which results in the enhanced light-to-electricity conversion efficiency from 1.4% with liquid to 1.82% with gel and 1.86% with solid electrolytes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Le-Qing Fan, Yuan Chen, Ji-Huai Wu, Yun-Fang Huang
Journal of Solid State Chemistry 2011 Volume 184(Issue 4) pp:899-904
Publication Date(Web):April 2011
DOI:10.1016/j.jssc.2011.02.019
Two new 4d–4f Ln–Ag heterometallic coordination polymers, {[Ln3Ag5(IN)10(H2O)7]·4(ClO4)·4(H2O)}n (Ln=Eu (1) and Sm (2), HIN=isonicotinic acid), have been synthesized under hydrothermal conditions by reactions of Ln2O3, AgNO3, HIN and HClO4, and characterized by elemental analysis, IR, thermal analysis and single-crystal X-ray diffraction. It is proved that HClO4 not only adjusts the pH value of the reaction mixture, but also acts as anion template. The structure determination reveals that 1 and 2 are isostructural and feature a novel two-dimensional (2D) layered hetrometallic structure constructed from one-dimensional Ln–carboxylate chains and pillared Ag(IN)2 units. The 2D layers are further interlinked through Ag⋯Ag and Ag⋯O(ClO4−) multiple weak interactions, which form a rare Ag–ClO4 ribbon in lanthanide–transition metal coordination polymers, to give rise to a three-dimensional supramolecular architecture. Moreover, the luminescent properties of these two compounds have also been investigated at room temperature.Graphical abstractTwo new anion-templated 2D 4d–4f Ln–Ag heterometallic coordination polymers based on novel lanthanide–carboxylate chains and pillared Ag(IN)2 units, {[Ln3Ag5(IN)10(H2O)7]·4(ClO4)·4(H2O)}n (Ln=Eu (1) and Sm (2), HIN=isonicotinic acid), have been hydrothermally synthesized and structurally characterized. 1 and 2 exhibit good luminescent properties.Research highlights► Two 2D Eu (Sm)–Ag coordination polymers templated by perchlorate anion have been synthesized. ► Polymers consist of novel 1D lanthanide–carboxylate chains. ► In both structures, there are rare Ag⋯Ag and Ag⋯O(ClO4−) multiple weak interactions.► Both compounds exhibit good luminescent properties.
Co-reporter:Le-Qing Fan, Ji-Huai Wu, Yun-Fang Huang
Journal of Solid State Chemistry 2011 Volume 184(Issue 9) pp:2472-2477
Publication Date(Web):September 2011
DOI:10.1016/j.jssc.2011.07.033
Two unusual pillared-layer 3d–4f Ln–Cu heterometallic coordination polymers, {[Ln2Cu5Br4(IN)7(H2O)6]·H2O}n (Ln=Eu (1) and Gd (2), HIN=isonicotinic acid), have been synthesized under hydrothermal conditions, and characterized by elemental analysis, IR, thermal analysis and single-crystal X-ray diffraction. The structure determination reveals that 1 and 2 are isostructural and feature a novel three-dimensional pillared-layer hetrometallic structure built upon the linkages of one-dimensional (1D) linear Ln–carboxylate chains, zero-dimensional (0D) Ln–carboxylate Ln2(IN)8 dimers, rare 1D zigzag [Cu5Br4]n inorganic chains and IN− pillars. In both 3D structures, there are Ln–carboxylate layers resulted from the connections of 1D Ln–carboxylate chains and 0D Ln2(IN)8 dimers through O–H⋯O hydrogen bondings. The luminescent properties of 1 have been investigated. The magnetic properties of 1 and 2 have also been studied.Graphical abstractTwo unusual pillared-layer Eu (Gd)–Cu heterometallic coordination polymers have been hydrothermally synthesized. The luminescent properties of Eu–Cu compound and magnetic properties of both compounds are investigated.Highlights► Two unusual 3D pillared-layer Eu (Gd)–Cu heterometallic coordination polymers have been synthesized. ► 1D and 0D Ln–carboxylate motifs construct layers by O–H⋯O hydrogen bondings. ► In both the structures, there are rare 1D zigzag Cu/Br inorganic chains. ► Luminescent properties of Eu–Cu compound and magnetic properties of both the compounds are investigated.
Co-reporter:Le-Qing Fan, Ji-Huai Wu, Yun-Fang Huang
Inorganic Chemistry Communications 2011 Volume 14(Issue 12) pp:1906-1910
Publication Date(Web):December 2011
DOI:10.1016/j.inoche.2011.09.008
An unusual three-dimensional (3D) pillared-layer 3d–4f (Cu+–Sm3+) heterometallic coordination polymer, {Sm2Cu7Br6(IN)7(H2O)5·3H2O}n (1) (HIN = isonicotinic acid), has been successfully synthesized by hydrothermal reaction of Sm2O3, CuBr2, HIN, HClO4 and H2O, and characterized by elemental analyses, IR, PXRD, and single-crystal X-ray diffraction. The structure determination reveals that 1 possesses 3D heterometallic framework constructed upon unprecedented [Cu7Br6]nn+ inorganic layers linked by dimeric Sm2(IN)6 pillars. Additionally, the thermogravimetric analysis and luminescent property of 1 were investigated and discussed.The {Sm2Cu7Br6(IN)7(H2O)5·3H2O}n is the first example of 3D 3d–4f heterometallic coordination polymer based on 2D Cu–Br inorganic layers.Research Highlights► A novel 3D Sm–Cu coordination polymer based on 2D Cu-Br layers has been synthesized. ► CuBr2N triangles and CuBr3N tetrahedra construct the unprecedented 2D Cu-Br layer. ► This compound exhibits good luminescent property.
Co-reporter:GenTian Yue;JiHuai Wu;YaoMing Xiao;HaiFeng Ye;JianMing Lin
Science Bulletin 2011 Volume 56( Issue 3) pp:325-330
Publication Date(Web):2011 January
DOI:10.1007/s11434-010-3080-0
Using blend heterojunction consisting of C60 derivatives [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and poly(3-hexylthiophene) (P3HT) as charge carrier transferring medium to replace I3−/I− redox electrolyte, a novel flexible dye-sensitized solar cell (DSSC) is fabricated. The characterization of infrared spectra and ultraviolet-visible spectra shows that the PCBM/P3HT heterojunction has not only the absorption in ultraviolet light for PCBM, but also the absorption in visible and near infrared light for P3HT, which widens the photoelectric response range for DSSC. The influence of PCBM/P3HT mass ratio on the performance of the solar cell is discussed. Under 100 mW cm−2 (AM 1.5) simulated solar irradiation, the flexible solar cell achieves a light-to-electric energy conversion efficiency of 1.43%, open circuit voltage of 0.87 V, short circuit current density of 3.0 mA cm−2 and fill factor of 0.54.
Co-reporter:GuiXiang Xie;JianMing Lin;JiHuai Wu;Zhang Lan;QingHua Li
Science Bulletin 2011 Volume 56( Issue 1) pp:96-101
Publication Date(Web):2011 January
DOI:10.1007/s11434-010-4115-2
An upconversion luminescence powder TiO2:(Er3+, Yb3+) is prepared by a hydrothermal method and used to fabricate dye-sensitized solar cell (DSSC). The TiO2:(Er3+, Yb3+) powder undergoes upconversion luminescence, converting infrared light which the dye can not absorb into visible light with wavelengths of 510–700 nm which the dye can absorb, increasing the photocurrent of the DSSC. TiO2:(Er3+, Yb3+) also acts as a p-type dopant, heightening the Fermi level of the oxide film, which increases the photovoltage of the DSSC. The best performance of the DSSC is found when the ratio of TiO2/luminescence powder is 1/3 in the luminescence layer. Under simulated solar irradiation of 100 mW cm−2 (AM 1.5), the DSSC containing TiO2:(Er3+, Yb3+) doping achieves a light-to-electricity energy conversion efficiency of 7.28% compared with 6.41% for the undoped DSSC.
Co-reporter:Gentian Yue;Jihuai Wu;Yaoming Xiao;Jianming Lin
Frontiers of Optoelectronics 2011 Volume 4( Issue 1) pp:108-113
Publication Date(Web):2011 March
DOI:10.1007/s12200-011-0203-4
[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) / poly (3-hexylthiophene) (P3HT) heterojunction has not only the absorption in ultraviolet light for PCBM, but also the absorption in visible light for P3HT, which widens the incident light harvest range, improving the photoelectrical response of hybrid solar cell effectively. Using conducting polymers blend heterojunction consisting of C60 derivatives PCBM and P3HT as charge carrier transferring medium to replace I3− =I− redox electrolyte and dye, a novel flexible solar cell was fabricated in this study. The influence of PCBM/P3HT mass ratio on the photovoltaic performance of the solar cell was also studied. Under a simulated solar irradiation of 100mW·cm−2, the flexible solar cell achieved a light-to-electric energy conversion efficiency of 1.04%, an open circuit voltage of 0.86 V, short circuit current density of 2.6 mA·cm−2 and fill factor (FF) of 0.46.
Co-reporter:Yunfang Huang, Yibin Li, Yuelin Wei, Miaoliang Huang, Jihuai Wu
Solar Energy Materials and Solar Cells 2011 95(3) pp: 1019-1027
Publication Date(Web):
DOI:10.1016/j.solmat.2010.12.017
Co-reporter:Gentian Yue;Jihuai Wu;Jianming Lin
Frontiers of Optoelectronics 2011 Volume 4( Issue 4) pp:369-377
Publication Date(Web):2011 December
DOI:10.1007/s12200-011-0181-6
A Poly (3, 4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS)/carbon conductive paste was prepared and coated on a conducting FTO glass to construct counter electrode for polymer heterojunction dye-sensitized solar cells (DSSCs). The surface morphology, conductivity, sheet resistance, redox properties and photoelectric properties of carbon electrode were observed respectively by scanning electron microscopy, four-probe tester and CHI660D electrochemical measurement system. The experimental results showed that DSSCs had the best photoelectric properties for PEDOT:PSS/carbon counter electrode annealing at 80°C in vacuum conditions. Using [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM)/poly (3-hexylthiophene) (P3HT) heterojunction to replace I3− =I− redox electrolyte, the overall energy conversion efficiency of the DSSCs with barrier layer reached 4.11% under irradiation of a simulated solar light with a intensity of 100mW·cm−1 (AM 1.5), which is higher 20% than that of the DSSCs with Pt counter electrode (3.42%). The excellent photoelectric properties, simple preparation procedure and low cost allow the PEDOT:PSS/carbon electrode to be a credible alternative used in DSSCs.
Co-reporter:Jihuai Wu, Guixiang Xie, Jianming Lin, Zhang Lan, Miaoliang Huang, Yunfang Huang
Journal of Power Sources 2010 Volume 195(Issue 19) pp:6937-6940
Publication Date(Web):1 October 2010
DOI:10.1016/j.jpowsour.2010.04.081
The doped rare-earth oxide europium-doped yttria (Y2O3:Eu3+) is introduced into the TiO2 film electrode in a dye-sensitized solar cell. As a luminescence medium, Y2O3:Eu3+ improves the light harvesting via a conversion luminescence process and increases the photocurrent, as a p-type dopant, Y2O3:Eu3+ elevates the energy level of the oxide film and increases the photovoltage. When the TiO2 electrode is doped by 3 wt.% Y2O3:Eu3+, the cell light-to-electric conversion efficiency is improved by a factor of 1.14 compared to that of a cell without Y2O3:Eu3+ doping.
Co-reporter:Ziying Tang, Jihuai Wu, Qinghua Li, Zhang Lan, Leqing Fan, Jianming Lin, Miaoliang Huang
Electrochimica Acta 2010 Volume 55(Issue 17) pp:4883-4888
Publication Date(Web):1 July 2010
DOI:10.1016/j.electacta.2010.03.081
A microporous hybrid of poly(glycidyl acrylate)–polypyrrole (PGA–PPy) was synthesized by a two-step solution polymerization. Using this hybrid as polymer host, a gel-electrolyte with high conductivity of 12.83 mS cm−1 was prepared. The researches by scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), and cyclic voltammetry (CV) show that the microporous structure and functional groups for PGA allows the higher absorbency and good ionic salt tolerance for the electrolyte, the introduction of PPy causes a lower charge-transfer resistance and higher electrocatalytic activity for the I3−/I− redox reaction for the electrolyte. Based on the electrolyte, a dye-sensitized solar cell with a light-to-electrical energy conversion efficiency of 5.03% is achieved, under illumination with a simulated solar light of 100 mW cm−2 (AM 1.5).
Co-reporter:Qinghua Li, Jihuai Wu, Ziying Tang, Yaoming Xiao, Miaoliang Huang, Jianming Lin
Electrochimica Acta 2010 Volume 55(Issue 8) pp:2777-2781
Publication Date(Web):1 March 2010
DOI:10.1016/j.electacta.2009.12.072
A novel gel polymer electrolyte based on poly(acrylic acid-g-gelatin)/polypyrrole with conductivity of 14.1 mS cm−1 was prepared. Based on the gel electrolyte, a flexible quasi-solid-state dye-sensitized solar cell was fabricated by using a low-temperature filming technique. Owing to high conductivity and the catalytic function of polypyrrole for I−/I3− redox reaction for the gel electrolyte, the flexible quasi-solid-state dye-sensitized solar cell showed a light-to-electric energy conversion efficiency of 1.28%, under a simulated solar light irradiation with intensity of 100 mW cm−2 (AM 1.5).
Co-reporter:Yaoming Xiao, Jihuai Wu, Gentian Yue, Guixiang Xie, Jianming Lin, Miaoliang Huang
Electrochimica Acta 2010 Volume 55(Issue 15) pp:4573-4578
Publication Date(Web):1 June 2010
DOI:10.1016/j.electacta.2010.03.011
Anatase titania nanotube (TNT) is prepared by two-steps hydrothermal growth method. Using the TNTs and titania particles (P25), a highly stable and uniform titania colloid without any sedimentation in 180 days is prepared by hydrothermal treatment. Based on the titania colloid, a flexible dye-sensitized solar cell (DSSC) is fabricated at low temperature. The influence of preparation conditions on the properties of TNTs and titania colloid is discussed by transmitting electron microscopy, scanning electron microscopy, selected area electron diffraction, X-ray diffraction, UV–vis absorption spectra, and Brunauer–Emmet–Teller surface area measurements. Under an optimized condition, a flexible DSSC with light-to-electric energy conversion efficiency of 4.0% is achieved under a simulated solar light irradiation of 100 mW cm−2 (AM 1.5).
Co-reporter:Jihuai Wu, Gentian Yue, Yaoming Xiao, Haifeng Ye, Jianming Lin, Miaoliang Huang
Electrochimica Acta 2010 Volume 55(Issue 20) pp:5798-5802
Publication Date(Web):1 August 2010
DOI:10.1016/j.electacta.2010.05.025
Co-reporter:Leqing Fan, Jihuai Wu, Yunfang Huang, Jianming Lin
Solid State Sciences 2010 Volume 12(Issue 4) pp:558-562
Publication Date(Web):April 2010
DOI:10.1016/j.solidstatesciences.2010.01.005
A new trinuclear magnetic lead iodide semiconductor PbI4[Cu(Me2dtc)(bipy)]2 (Me2dtc = N,N-dimethyldithiocarbamate, bipy = 2,2′-bipyridine) has been synthesized, and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P21/c with a = 22.2137(11) Å, b = 11.3687(4) Å, c = 15.3382(8) Å, β = 102.372(3)°, Z = 4, V = 3783.6(3) Å3. It is built up by [PbI4S2] octahedron linked with two [CuIS2N2] square pyramids through common edges. The adjacent molecules stack with each other to form a two-dimensional (2D) layer along ab plane via the π–π stacking interactions between aromatic groups of bipy ligands. Then the 2D layers are further extended into a three-dimensional structure through hydrogen bonding interactions. The temperature dependence of the electrical conductivity indicates that this compound exhibits semiconducting character. The title brown–black compound has an optical bandgap of 1.26 eV, and the variable-temperature magnetic susceptibility measurement indicates weak antiferromagnetic behavior with J = −1.06 cm−1.
Co-reporter:Zhang Lan;Jihuai Wu;Jianming Lin ;Miaoliang Huang
Journal of Applied Polymer Science 2010 Volume 116( Issue 3) pp:1329-1333
Publication Date(Web):
DOI:10.1002/app.31564
Abstract
A kind of thermosetting organic solvent free polymer gel electrolyte with oligomer ethylene glycol as liquid phase was prepared and applied in quasi-solid-state dye-sensitized solar cell (QS-DSSC). The viscosity and the ionic conductivity of the polymer gel electrolyte are sensitive to the changed temperature. The photovoltaic performance of QS-DSSC is also improved with the increased temperature due to the increased ionic conductivity and diffusion coefficient of iodide in polymer gel electrolyte. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Jianming Lin;Qunwei Tang;Jihuai Wu;Qinghua Li
Journal of Applied Polymer Science 2010 Volume 116( Issue 3) pp:1376-1383
Publication Date(Web):
DOI:10.1002/app.31642
Abstract
A simple, two-step aqueous polymerization was introduced to synthesize a polyacrylate (PAC)/polypyrrole (PPy) hydrogel. The hydrogel had a semi-interpenetrating network (semi-IPN) structure with a loose, three-dimensional PAC network and a one-dimensional PPy conjugated chain. The presence of PPy led to a higher conductivity (9.1 mS/cm) for the PAC/PPy hydrogel. Because of the acrylate group on PAC and the imine group on PPy, the hydrogel showed typical pH sensitivity with two water absorption peaks at pH 4–6 and pH > 11. The loose semi-IPN structure endowed the hydrogel with good load and release functions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Qunwei Tang;Qinghua Li;Jianming Lin;Shijun Fan;De Hu ;Jihuai Wu
Polymer Composites 2010 Volume 31( Issue 1) pp:145-151
Publication Date(Web):
DOI:10.1002/pc.20777
Abstract
Exfoliated graphite nanoplatelets were modified by hexadecyltrimethylammonium bromide (C16TAB) and were used for the construction of [poly(acrylic acid)/graphite]n [(PAA/G)n] multilayer films using a layer-by-layer (LBL) self-assembly method. The film thickness was monitored using X-ray diffraction technique; the results showed that the thickness depended on pH of PAA. Under a lower pH value such as 1.5, the average bilayer thickness was 1.5 nm. Once the pH of PAA was increased to 6.5, the bilayer thickness was around 30 nm. The C16TAB modified (PAA/G)n multilayer films showed high thermal stability and electrical conductivity. A percolation phenomenon occurred at bilayer number of 11, and the mechanism was discussed. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Co-reporter:Zhang Lan;Jihuai Wu;Jianming Lin
Journal of Materials Science: Materials in Electronics 2010 Volume 21( Issue 10) pp:1000-1004
Publication Date(Web):2010 October
DOI:10.1007/s10854-010-0083-1
The super-porous TiO2 film is prepared with the block copolymer Pluronic F-127 as porous template. Comparing with the commonly used meso-porous TiO2 film prepared with Polyethylene glycol 20,000 as pore former, the super-porous TiO2 film shows higher photovoltaic performance when integrated it into polymer gel electrolyte based quasi-solid-state dye-sensitized solar cell (QS-DSSC). The enhanced dye adsorption, light scattering properties of the super-porous TiO2 film improve the utilization efficiency of sun light to be converted to electricity. Moreover, the special microstructures of the super-porous TiO2 film also makes for the deep penetration of polymer gel electrolyte into the dye-coated TiO2 film, which is the prerequisite for highly photovoltaic performance of polymer gel electrolyte-based dye-sensitized solar cell. So it presents a feasible way to enhance the photovoltaic performance of QS-DSSC.
Co-reporter:Zhang Lan;Jihuai Wu;Jianming Lin
Journal of Materials Science: Materials in Electronics 2010 Volume 21( Issue 8) pp:833-837
Publication Date(Web):2010 August
DOI:10.1007/s10854-009-0003-4
The sub-micron size anatase TiO2 particles with size about 0.2-0.3 μm were synthesized with basic peptizing agent and hydrothermal method and added into TiO2 film as light scattering center. The addition of the sub-micron size anatase TiO2 particles enhanced light scattering and dye adsorption abilities of the TiO2 film. When the weight proportion of the sub-micron size/nano-size TiO2 particles in the TiO2 film attained to 1.25/10, the highest energy conversion efficiency about 7.41% was obtained, which was 23% enhancement comparing with the TiO2 film containing pure nano-size TiO2 particles. It presented an efficient way for improving the photovoltaic performance of dye-sensitized solar cell.
Co-reporter:Yunfang Huang, Yuelin Wei, Shuhong Cheng, Leqing Fan, Yibin Li, Jianmin Lin, Jihuai Wu
Solar Energy Materials and Solar Cells 2010 94(5) pp: 761-766
Publication Date(Web):
DOI:10.1016/j.solmat.2009.12.020
Co-reporter:YaoMing Xiao;JiHuai Wu;QingHua Li;GuiXiang Xie;GenTian Yue
Science Bulletin 2010 Volume 55( Issue 10) pp:980-985
Publication Date(Web):2010 April
DOI:10.1007/s11434-009-0528-1
A TiO2 slurry was prepared by hydrothermal treating mixture of commercial TiO2 (P25), ethanol and distilled water in an autoclave. A flexible photoanode and dye-sensitized solar cell (DSSC) was fabricated on an ITO-coated poly (ethylene naphthalate) sheet (ITO/PEN) substrate by a doctor-blade technique. The sample was characterized with SEM, UV-vis, FTIR, and the photoelectric properties of the DSSC were measured. The influence of preparation conditions on the properties of the flexible DSSC was investigated. It is found that the TiO2 slurry hydrothermally treated in 185°C for 12 h has good stability and uniformity. Based on the slurry, a flexible DSSC with light-to-electric conversion efficiencies of 3.4% is achieved under irradiation with a simulate solar light intensity of 100 mW/cm2.
Co-reporter:Zhang Lan;JiHuai Wu;JianMing Lin;MiaoLiang Huang
Science China Chemistry 2010 Volume 53( Issue 6) pp:1352-1357
Publication Date(Web):2010 June
DOI:10.1007/s11426-010-3204-z
N-cetylpyridinium iodide (N-CPI) as a new electric additive for enhancing photovoltaic performance of the dye-sensitized solar cell (DSSC) was studied. It showed high efficiency for enhancing both the open-circuit voltage and the short-circuit current density of DSSC when the suitable amount of N-CPI as 0.02 M was added in liquid electrolyte. The energy conversion efficiency of DSSC increased from 4.429% to 6.535%, with 47.55% enhancement. Therefore, it is a highly efficient electric additive for DSSC. The intrinsic reason is owing to the special molecular structure of N-CPI, which contains two different polarity groups. As a surfactant, N-CPI could form ordered arrangement in liquid electrolyte, which affects the diffusing ability and the redox reaction of I−/I3−, and further affects the photovoltaic performance of DSSC.
Co-reporter:Zhang Lan;Jihuai Wu;Jianming Lin
Journal of Sol-Gel Science and Technology 2010 Volume 53( Issue 3) pp:599-604
Publication Date(Web):2010 March
DOI:10.1007/s10971-009-2137-5
An organic–inorganic composite electrolyte with tetra-n-butyl titanate and ethylene glycol is prepared with sol–gel method and used in fabricating solid state dye-sensitized solar cell (S-DSSC). The addition of acetyl acetone into the composite electrolyte can extend the solidification time to meet the time requirement for assembling S-DSSC. The addition of 4-tert-butylpyridine can enhance the photovoltaic performance of S-DSSC due to its efficient suppressing of dark current in S-DSSC. Furthermore, with the addition of catalytic functional polypyrrole nanoparticles for transformation of iodide/triiodide redox couples in the composite electrolyte, the energy conversion efficiency of S-DSSC increases from 3.147 to 3.597%, with 14% enhancement.
Co-reporter:Zhang Lan, Jihuai Wu, Sancun Hao, Jianming Lin, Miaoliang Huang and Yunfang Huang
Energy & Environmental Science 2009 vol. 2(Issue 5) pp:524-528
Publication Date(Web):25 Feb 2009
DOI:10.1039/B821908G
A kind of closed-microporous hybrid with poly(acrylic acid)-poly(ethylene glycol)-polypyrrole (PAA-PEG-PPy) was synthesized template-free by in situ polymerization and micro-phase separation of PPy in PAA-PEG gel. This novel structure hybrid was used as a matrix in preparing polymer gel electrolytes for quasi-solid-state dye-sensitized solar cells (QS-DSSC). It shows high liquid electrolyte absorbency and salt tolerance, which are benefits for improving photovoltaic performance of QS-DSSC.
Co-reporter:Qunwei Tang, Jihuai Wu, Xiaoming Sun, Qinghua Li, Jianming Lin and Miaoliang Huang
Chemical Communications 2009 (Issue 16) pp:2166-2167
Publication Date(Web):23 Feb 2009
DOI:10.1039/B821358E
By polymerization at 80 °C and crystal growth at 0 °C, highly oriented polyaniline flake and fiber arrays were self-assembled without any templates or surfactants.
Co-reporter:Pinjiang Li, Jihuai Wu, Jianming Lin, Miaoliang Huang, Yunfang Huang, Qinghua Li
Solar Energy 2009 Volume 83(Issue 6) pp:845-849
Publication Date(Web):June 2009
DOI:10.1016/j.solener.2008.11.012
Pt/Carbon black counter electrode for dye-sensitized solar cells (DSSCs) was prepared by reducing H2PtCl6 with NaBH4 in carbon black. The Pt/Carbon black electrode had a high electrocatalytic activity for iodide/triiodide redox reaction. Using the Pt/Carbon black counter electrode, DSSC achieved 6.72% energy conversion efficiency under one sun illumination. Pt/Carbon black electrode shows the same energy conversion efficiency and lower cost compared with Pt electrode, which makes it available in DSSCs practical applications.
Co-reporter:Qunwei Tang, Jihuai Wu, Xiaoming Sun, Qinghua Li, Jianming Lin
Journal of Colloid and Interface Science 2009 Volume 337(Issue 1) pp:155-161
Publication Date(Web):1 September 2009
DOI:10.1016/j.jcis.2009.04.069
Highly oriented polyaniline (PANI) fiber was prepared by a polymerization at higher temperature and growth in lower temperature. Poly(sodium styrenesulfonate)/polyaniline multilayer film (PSS/PANI)n was layer-by-layer molecular-level self-assembled by a simple technique. The morphology and structure of the oriented PANI fiber were characterized, showing an emeraldine state and ordered molecular structure. The growth process and surface topography of the (PSS/PANI)n multilayer film were characterized by UV–vis spectroscopy and atomic force microscopy. Absorbance plotted against the bilayers exhibited a linear dependence, indicating a progressive and uniform deposition process of the multilayer film. The (PSS/PANI)n multilayer film exhibited an electrical conductivity in the order of 1 S cm−1, and when bilayer number exceeded a threshold value of 4, the conductivity of the multilayer film increased dramatically. The electrochemical properties were studied through cyclic voltammograms, and it was found that the electrochemical activity of the (PSS/PANI)n film increased with the increase of the bilayer number.A poly(sodium styrenesulfonate)/polyaniline multilayer film (PSS/PANI)n was layer-by-layer self-assembled by repeatedly dipping highly oriented polyaniline and poly(sodium styrenesulfonate).
Co-reporter:Yibin Li, Jihuai Wu, Yunfang Huang, Miaoliang Huang, Jianming Lin
International Journal of Hydrogen Energy 2009 Volume 34(Issue 19) pp:7927-7933
Publication Date(Web):October 2009
DOI:10.1016/j.ijhydene.2009.07.047
A new layered compound K2.33Sr0.67Nb5O14.335 was prepared and its full structure was characterized by single crystal diffraction of K2.33Sr0.67Nb5O14.335, which belongs to Tetragonal layered perovskite phase. The band structure of K2.33Sr0.67Nb5O14.335 was calculated by CASTEP code based on the density functional theory (DFT). H2.33Sr0.67Nb5O14.335 was prepared by a proton exchange of K2.33Sr0.67Nb5O14.335, and followed with successive reaction to obtain Pt incoporated sample. Using H2.33Sr0.67Nb5O14.335/Pt as catalyst, the photocatalytic H2 evolution rate reached 153.1 cm3 h−1 g−1 in 10 vol.% methanol aqueous solution under irradiation with wavelength more than 290 nm from a 100 W mercury lamp.
Co-reporter:Yunfang Huang, Yuelin Wei, Leqing Fan, Miaoliang Huang, Jianmin Lin, Jihuai Wu
International Journal of Hydrogen Energy 2009 Volume 34(Issue 13) pp:5318-5325
Publication Date(Web):July 2009
DOI:10.1016/j.ijhydene.2009.04.040
HLaNb2O7 photocatalyst was prepared by the proton exchange reaction of KLaNb2O7 with diluted acid. The layered perovskite KLaNb2O7 has been successfully synthesized by the polymerized complex method. The product was characterized by X-ray diffraction, ultraviolet–visible spectra, scan electron microscope, TG–DSC, specific surface area, and FTIR. The layered perovskite KLaNb2O7 was formed at a lower calcination temperature (1000 °C, 6 h) by the polymerized complex method than a solid-state reaction method (1150 °C, 24 h). Photocatalytic decomposition of water to produce hydrogen under UV irradiation with methanol as electron donor was studied over layered perovskite HLaNb2O7 photocatalysts. The HLaNb2O7 photocatalyst prepared by the polymerized complex method showed much higher activity than that prepared by conventional solid-state reaction method.
Co-reporter:Qunwei Tang, Xiaoming Sun, Qinghua Li, Jihuai Wu, Jianming Lin, Miaoliang Huang
Materials Letters 2009 Volume 63(Issue 5) pp:540-542
Publication Date(Web):28 February 2009
DOI:10.1016/j.matlet.2008.11.028
We first report the synthesis of oriented polyaniline (PANI) flake arrays by a self-assembly method with inorganic acid as a dopant. It is found that the morphology and molecular structure depend on aniline concentration. FTIR and XRD results reveal that the oriented PANI flake arrays are in high conductive emeraldine state, which is expected to show excellent electrochemical properties. Cyclic voltammograms of I2/I– system measurement shows that the oriented PANI flake arrays present small charge-transfer resistance and high electrocatalytic activity. The oriented PANI flake arrays are expected to be useful in electrical, optical and electrochemical devices.
Co-reporter:Jianming Lin;Qunwei Tang;Jihuai Wu;Hui Sun;Shijun Fan ;De Hu
Polymer Composites 2009 Volume 30( Issue 8) pp:1132-1137
Publication Date(Web):
DOI:10.1002/pc.20669
Abstract
Cu microparticles are dispersed in a polyacrylamide (PAM) superabsorbent by a two steps aqueous solution polymerization. Based on the electrical conductivity of Cu and the water absorbency of PAM, a novel conducting hydrogel (PAM/Cu) with a conductivity of 6.12 mS cm−1 and percolation threshold of 3 wt% is prepared. An appended network structure model for explaining the electrical conduction of PAM/Cu hydrogel is proposed. And the effects of crosslinker, initiator, monomer concentration, Cu content, reaction temperature, water absorbency on the electrical conductivity are also investigated according to the structure model. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Co-reporter:Haiyong Ao;Miaoliang Huang;Jihuai Wu;Jianming Lin;Qunwei Tang ;Hui Sun
Polymers for Advanced Technologies 2009 Volume 20( Issue 12) pp:1044-1049
Publication Date(Web):
DOI:10.1002/pat.1361
Abstract
Poly(acrylamide-co-acrylic acid)/polyacrylamide [P(AM-co-AA)/PAM] hydrogel with superporous and interpenetrating network (IPN) structure was prepared by a prepolymerization reaction and a synchronous polymerization reaction and frothing process. Scanning electron microscope (SEM) images show that the resultant hydrogel possesses abundant interconnected pores. DSC indicates that the porous structure enhances the swelling ratio and reduces the interaction between water and the hydrogel. In contrast, the IPN by PAM decreases water absorbency and enhances water retentivity. It is found that a superporous stucture in the hydrogel increases the equilibrium swelling ratio and decreases the compressive strength of the hydrogel. On the other hand, the increase in AM oligomer (oligo-AM) amount decreases the equilibrium swelling ratio and improves the compressive strength of the hydrogel. Therefore, the two-steps synthesis method can be used to construct a hydrogel with superporous and IPN structure. The swelling and mechanical properties of the hydrogel can be improved effectively. Copyright © 2008 John Wiley & Sons, Ltd.
Co-reporter:Qunwei Tang;Jihuai Wu;Hui Sun;Shijun Fan;De Hu ;Jianming Lin
Polymer Composites 2009 Volume 30( Issue 8) pp:1183-1189
Publication Date(Web):
DOI:10.1002/pc.20676
Abstract
A novel polyacrylate/poly(ethylene glycol) (PAA/PEG) hydrogel was synthesized by a simple two-step aqueous prepolymerization method. The deswelling properties were investigated in the case of changing the neutralization degrees of PAA, the pHs and the concentration of multivalent salt solutions. Methyl orange (MO) dye can be adsorbed and released using the swelling–deswelling property of the PAA/PEG hydrogel. The PAA/PEG hydrogel can adsorb MO of 29 mg/g at equilibrium and release about 80% in 30 min. Based on the deswelling property, the dyes in wastewater can be reclaimed and reused. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Co-reporter:Qinghua Li;Jihuai Wu;Qunwei Tang;Zhang Lan;Pinjiang Li ;Tingting Zhang
Polymer Composites 2009 Volume 30( Issue 11) pp:1687-1692
Publication Date(Web):
DOI:10.1002/pc.20743
Abstract
A polymer gel electrolyte with ionic conductivity of 5.11 mS cm−1 was prepared by using poly (acrylonitrile-co-styrene) as polymer matrix, acetonitrile and tetrahydrofuran as binary organic mixture solvent, NaI + I2 as electrolyte, graphite powder and 1-methylimidazole as additives. The components ratio of the polymer gel electrolyte was optimized, and the influence of the components and temperature on the ionic conductivity of the polymer gel electrolyte and photoelectronic properties of dye sensitized solar cell were investigated. On the basis of the polymer gel electrolyte with the optimized conditions, a quasi-solid-state dye-sensitized solar cell was fabricated and its light- to-electricity energy conversion efficiency of 3.25% was achieved under irradiation of 100 mW cm−2. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Co-reporter:Qunwei Tang;Xiaoming Sun;Jihuai Wu;Qinghua Li ;Jianming Lin
Polymer Engineering & Science 2009 Volume 49( Issue 9) pp:1871-1878
Publication Date(Web):
DOI:10.1002/pen.21409
Abstract
A novel poly(acrylic acid-g-gelatin)/graphite composite is synthesized by aqueous solution polymerization. Based on the electrical conductivity of graphite nanoplatelets and the absorbency of poly(acrylic acid-g-gelatin)/graphite, a novel conducting gel with a conductivity of 3.18 mS cm−1 is prepared. The effects of synthesis parameters on the electrical conductivity of the gels are investigated in detail. An appended network structure model of the poly(acrylic acid-g-gelatin)/graphite conducting gel is proposed. The conducting gel presents a high mechanical strength in cyclohexane, which is important for the gel applications. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Co-reporter:Yuelin Wei, Jing Li, Yunfang Huang, Miaoliang Huang, Jianming Lin, Jihuai Wu
Solar Energy Materials and Solar Cells 2009 93(8) pp: 1176-1181
Publication Date(Web):
DOI:10.1016/j.solmat.2009.02.001
Co-reporter:Qunwei Tang, Jihuai Wu, Xiaoming Sun, Qinghua Li, Jianming Lin, Leqing Fan
Polymer 2009 50(3) pp: 752-755
Publication Date(Web):
DOI:10.1016/j.polymer.2008.11.052
Co-reporter:Qunwei Tang;Xiaoming Sun;Qinghua Li;Jianming Lin
Journal of Materials Science 2009 Volume 44( Issue 14) pp:3712-3718
Publication Date(Web):2009 July
DOI:10.1007/s10853-009-3496-6
In this article, we successfully designed and fabricated polyacrylate/poly(ethylene glycol) interpenetrating network (PAC/PEG IPN) hydrogel by a two-step technique. The influences of synthesis parameters, such as crosslinker dosage and neutralization degree of PAC, on the equilibrium swelling ratio (SR) of the PAC/PEG IPN hydrogel were investigated. Based on Flory theory, a simplified experiential formula \( Q_{{{\text{H}}_{2} {\text{O}}}}^{5/3} = 14.72I^{ - 1} + 207.43 \) was proposed. The results revealed that the theoretical SR of the PAC/PEG IPN hydrogel was consistent with experimental value in the presence of univalent salt solution. In this case, the SR of the hydrogel can be calculated without measurement. While for multivalent salt solutions, the theoretical and experimental results are inconsistent owing to chelations between carboxylic and carboxylate groups of the PAC/PEG hydrogels and the cations in the solution.
Co-reporter:Qunwei Tang;Xiaoming Sun;Qinghua Li;Jianming Lin
Journal of Materials Science 2009 Volume 44( Issue 3) pp:726-733
Publication Date(Web):2009 February
DOI:10.1007/s10853-008-3173-1
A simple two-step aqueous polymerization method was introduced to synthesize polyacrylate/polyethylene glycol (PAC/PEG) interpenetrating network (IPN) hydrogel. The sorption behaviors and mechanism were studied by the sorption of PAC/PEG IPN hydrogel to Fe3+ ion from aqueous solution. The experimental results revealed that the adsoption amount of Fe3+ ion using swollen hydrogels was much higher than that using the dried composite, they were 75.69 mg/g and 14.25 mg/g, respectively. The parameters, such as neutralization degree, acrylic acid (AA) dosages and temperature, on the sorption amount of PAC/PEG IPN hydrogel were detailedly investigated.
Co-reporter:Qunwei Tang, Jihuai Wu, Xiaoming Sun, Qinghua Li and Jianming Lin
Langmuir 2009 Volume 25(Issue 9) pp:5253-5257
Publication Date(Web):March 20, 2009
DOI:10.1021/la8038544
Oriented polyaniline (PANI) microstructures (e.g., bulks, spheres, flakes, and fibers) were prepared without a template by polymerization at 80 °C and crystal growth at 0 °C and using a self-assembly method in the presence of hydrochloric acid (HCl) as the dopant. It was found that the shape and size of the resulting PANI microstructures depended on the HCl dosage and aniline concentration. Polyanilinium salt precipitates, as a templete, drive the formation of highly oriented PANI microstructures. The infrared and UV−vis absorption spectra and X-ray diffraction were used to characterize the molecular structures of the PANI microstructures. The results showed that their main structure was identical to those of the emeraldine salt form of PANI.
Co-reporter:Qunwei Tang, Xiaoming Sun, Qinghua Li, Jihuai Wu, Jianming Lin
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2009 Volume 346(1–3) pp:91-98
Publication Date(Web):20 August 2009
DOI:10.1016/j.colsurfa.2009.05.031
Hydrogels have potential applications in many fields, but the poor mechanical strength has limited their further development. In this article, we designed a high-strength hydrogel with an interpenetrating network (IPN) structure from polyacrylamide (PAM) and poly(vinyl alcohol) (PVA). Synthesis parameters, such as PVA/AM mass ratio, crosslinker dosage and elongation time were carried out for high tensile strength and elongation. The results showed that chemical crosslinking, physical entanglement and PVA precipitates were the dominant parameters for the improvement of mechanical properties. The PVA structure transferred from crystal to amorphous due to intermolecular and intramolecular interactions (such as hydrogen bond and self-crosslinking). PVA precipitates scatterred in the brittle PAM matrix homogeneously which dispersed the applied stress and improved the hydrogel toughness. The tensile strength and elongation were extremely high, they were 2.4 MPa and 3100%, respectively. The simple method is versatile in synthesizing high-strength IPN hydrogels using many kinds of polymer species.
Co-reporter:Jianming Lin, Qunwei Tang, De Hu, Xiaoming Sun, Qinghua Li, Jihuai Wu
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2009 Volume 346(1–3) pp:177-183
Publication Date(Web):20 August 2009
DOI:10.1016/j.colsurfa.2009.06.011
In this article, we reported the synthesis, structure and electric field sensitivity of polyacrylate/polyaniline (PAA/PANI) and poly(2-acrylamido-2-methyl propylsulfonic acid-acrylic acid)/polyaniline [P(AMPS-AA)/PANI] conducting hydrogels with an interpenetrating polymer network (IPN) structure. Scanning electron microscope showed that the conducting hydrogels presented porous structures consisting of PANI nanofibers. The results of Fourier-transform infrared and X-ray diffraction revealed that the PANI was in its conductive emeraldine state and partial crystallization. The unique morphology and molecular structure of the conducting hydrogels were expected to show unusual electric field responses. The conducting hydrogels were subjected to an electric field in NaCl solution for bending behaviors. It was demonstrated that the electric field response was improved by increasing aniline dosage, applied voltage and concentration of aqueous NaCl solution. The bending mechanism was attributed to polyelectrolyte hydrogel matrix and emeraldine PANI nanofibers.
Co-reporter:Jihuai Wu, Qinghua Li, Leqing Fan, Zhang Lan, Pinjiang Li, Jianming Lin, Sanchun Hao
Journal of Power Sources 2008 Volume 181(Issue 1) pp:172-176
Publication Date(Web):15 June 2008
DOI:10.1016/j.jpowsour.2008.03.029
Polypyrrole (PPy) nanoparticle was synthesized and coated on a conducting FTO glass to construct PPy counter electrode used in dye-sensitized solar cell (DSSC). Scanning electron microscope images show that PPy with porous and particle diameter in 40–60 nm is covered on the FTO glass uniformly and tightly. Cyclic voltammograms of I2/I− system measurement reveals that the PPy electrode has smaller charge-transfer resistance and higher electrocatalytic activity for the I2/I− redox reaction than that Pt electrode does. Overall energy conversion efficiency of the DSSC with the PPy counter electrode reaches 7.66%, which is higher (11%) than that of the DSSC with Pt counter electrode. The excellent photoelectric properties, simple preparation procedure and inexpensive cost allow the PPy electrode to be a credible alternative used in DSSCs.
Co-reporter:Jihuai Wu, Sancun Hao, Jianming Lin, Miaoliang Huang, Yunfang Huang, Zhang Lan and Pinjiang Li
Crystal Growth & Design 2008 Volume 8(Issue 1) pp:247
Publication Date(Web):November 27, 2007
DOI:10.1021/cg070232a
Anatase TiO2 nanocrystals were synthesized by hydrolysis of titanium isopropoxide followed by crystal growth under hydrothermal conditions in an acidic or basic environment. The crystal phase, crystal shape, and surface orientation of the TiO2 nanocrystals, as well as the photovoltaic performance of DSSCs, was studied by XRD, TEM, HRTEM, FTIR, and DSC-TG. It was found that anatase TiO2 nanocrystals prepared in tetramethylammonium hydroxide contained more {101} faces and presented a bipyramidal rod-like shape in comparison with the anatase TiO2 nanocrystal with a tetragonal ball-like shape prepared in nitric acid. The anatase-to-rutile phase transition temperature was largely affected by the crystal shape and surface orientation; it was about 950 °C for rod-like anatase and 700 °C for ball-like anatase. A 6.2% photoelectric conversion efficiency was obtained from the dye-sensitized solar cell (DSSC) with rod-like anatase, and a 5.4% the efficiency was obtained from the DSSC with ball-like anatase, which means that the anatase TiO2 nanocrystal prepared in tetramethylammonium hydroxide should be preferred for DSSCs.
Co-reporter:Yunfang Huang, Yanmei Xie, Leqing Fan, Yibin Li, Yuelin Wei, Jianmin Lin, Jihuai Wu
International Journal of Hydrogen Energy 2008 Volume 33(Issue 22) pp:6432-6438
Publication Date(Web):November 2008
DOI:10.1016/j.ijhydene.2008.08.048
The photocatalysts H1−xLaxCa2−xNb3O10 (x = 0, 0.25, 0.5, 0.75) was synthesized by conventional solid state reaction followed by an ion-exchange reaction. They were characterized by power X-ray diffraction, UV–vis diffusive reflectance and scan electron microscope. The effect of substitution of La3+ for Ca2+ in HCa2Nb3O10 has been studied on the photocatalytic decomposition of water under UV light irradiation with methanol as electron donor and Pt as promoter catalyst. Both the optical property and photocatalytic activity of H1−xLaxCa2−xNb3O10 were varied by the substitution of La3+ for Ca2+. The x value in H1−xLaxCa2−xNb3O10 had an important effect on the photocatalytic activity of the catalyst. When the x = 0.5, the H1−xLaxCa2−xNb3O10/Pt showed a photocatalytic activity of 169 cm3 h−1 g−1 hydrogen evolution rate in 10 vol.% methanol solution under irradiation from a 100 W mercy lamp at 333 K.
Co-reporter:Hongxun Yang, Miaoliang Huang, Jihuai Wu, Zhang Lan, Sancun Hao, Jianming Lin
Materials Chemistry and Physics 2008 Volume 110(Issue 1) pp:38-42
Publication Date(Web):15 July 2008
DOI:10.1016/j.matchemphys.2008.01.010
Using poly(methyl methacrylate) as polymer host, ethylene carbonate, 1,2-propanediol carbonate and dimethyl carbonate as organic mixture solvents, sodium iodide and iodine as source of I−/I3−, a polymer gel electrolyte PMMA–EC/PC/DMC–NaI/I2 with ionic conductivity of 6.89 mS cm−1 was prepared. Based on the polymer gel electrolyte, a quasi-solid-state dye-sensitized solar cell (DSSC) was fabricated. The quasi-solid-state DSSC possessed a good long-term stability and a light-to-electrical energy conversion efficiency of 4.78% under irradiation of 100 mW cm−2 simulated sunlight, which is almost equal to that of DSSC with a liquid electrolyte.
Co-reporter:Qunwei Tang;Jianming Lin ;Jihuai Wu
Journal of Applied Polymer Science 2008 Volume 108( Issue 3) pp:1490-1495
Publication Date(Web):
DOI:10.1002/app.27716
Abstract
Polyacrylamide/graphite superabsorbent composite was synthesized by free radical polymerization of acrylamide monomer using N,N′-methylene-bis-acrylamide as crosslinker, potassium persulfate as initiator, and graphite as functional filler. On the basis of the superabsorbent composite, a hydrogel with a conductivity of 0.86 mS cm−1 was obtained. The preparation conditions were optimized. The influence of crosslinker, initiator, monomer, graphite, water absorbency, and temperature on the conductivity of the hydrogel was investigated, an adsorbed network structure model for polyacrylamide/graphite conducting hydrogel was purposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Co-reporter:Jianming Lin;Qunwei Tang;Jihuai Wu;Hui Sun
Journal of Applied Polymer Science 2008 Volume 110( Issue 5) pp:2862-2866
Publication Date(Web):
DOI:10.1002/app.28871
Abstract
The conductive polypyrrole (PPy) is intercalated into the interlayers of expanded vermiculite (EVMT) to produce the nanocomposite with high conductivity by a synchronous polymerization of pyrrole and intercalation of PPy reaction in aqueous solution. The structures and properties are characterized by the nanocomposite using powder X-ray diffraction, Fourier transform infrared spectroscopy, conductivity measurements, and stability measurements. The nanocomposite exhibited a typical percolation phenomena and the percolation threshold is around mass ratio for pyrrole to EVMT 0.22. Under optimized conditions, a PPy/EVMT intercalated nanocomposite with conductivity of 67 S cm−1 is obtained. The intercalated nanocomposite has a good environmental stability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Co-reporter:J. H. Wu;S. C. Hao;Z. Lan;J. M. Lin;M. L. Huang;Y. F. Huang;L. Q. Fang;S. Yin;T. Sato
Advanced Functional Materials 2007 Volume 17(Issue 15) pp:
Publication Date(Web):21 AUG 2007
DOI:10.1002/adfm.200600621
Dye-sensitized solar cells (DSSCs) are receiving considerable attention as low-cost alternatives to conventional solar cells. In DSSCs based on liquid electrolytes, a photoelectric efficiency of 11 % has been achieved, but potential problems in sealing the cells and the low long-term stability of these systems have impeded their practical use. Here, we present a thermoplastic gel electrolyte (TPGE) as an alternative to the liquid electrolytes used in DSSCs. The TPGE exhibits a thermoplastic character, high conductivity, long-term stability, and can be prepared by a simple and convenient protocol. The viscosity, conductivity, and phase state of the TPGE can be controlled by tuning the composition. Using 40 wt % poly(ethylene glycol) (PEG) as the polymeric host, 60 wt % propylene carbonate (PC) as the solvent, and 0.65 M KI and 0.065 M I2 as the ionic conductors, a TPGE with a conductivity of 2.61 mS cm–2 is prepared. Based on this TPGE, a DSSC is fabricated with an overall light-to-electrical-energy conversion efficiency of 7.22 % under 100 mW cm–2 irradiation. The present findings should accelerate the widespread use of DSSCs.
Co-reporter:Jihuai Wu, Zhang Lan, Jianming Lin, Miaoliang Huang, Pinjiang Li
Journal of Power Sources 2007 Volume 173(Issue 1) pp:585-591
Publication Date(Web):8 November 2007
DOI:10.1016/j.jpowsour.2007.04.085
The effect of solvents in liquid electrolyte on the photovoltaic performance of dye-sensitized solar cells was investigated. The solvents with large donor number enhanced the open-circuit voltage but reduced the short-circuit current density. By mixing 30 vol.% NMP with 70 vol.% GBL, the open-circuit voltage increased from 0.55 to 0.632 V and the fill factor increased from 0.607 to 0.613 while the short-circuit current density decreased little. The further addition of 0.4 M pyridine into the above mixed solvent caused a huge increase of overall conversion efficiency from 5.73 to 6.70% under irradiation of 100 mW cm−2.
Co-reporter:Zhang Lan, Jihuai Wu, Jianming Lin, Miaoliang Huang
Journal of Power Sources 2007 Volume 164(Issue 2) pp:921-925
Publication Date(Web):10 February 2007
DOI:10.1016/j.jpowsour.2006.11.011
A novel efficient absorbent for liquid electrolyte based on poly(acrylic acid)–poly(ethylene glycol) (PAA–PEG) hybrid is prepared. The highest value of liquid electrolyte absorbency about 3.65 is achieved. The polymer gel electrolyte shows a moderate value of ionic conductivity about 3.24 mS cm−1 and high chemical stability. Based on the polymer gel electrolyte, a quasi-solid-state dye-sensitized solar cell was fabricated and its overall energy conversion efficiency of 3.19% was obtained under irradiation of 100 mW cm−2.
Co-reporter:Zhang Lan, Jihuai Wu, Jianming Lin, Miaoliang Huang, Shu Yin, Tsugio Sato
Electrochimica Acta 2007 Volume 52(Issue 24) pp:6673-6678
Publication Date(Web):1 August 2007
DOI:10.1016/j.electacta.2007.04.076
A new kind of polymer gel electrolyte based on poly(acrylic acid)–poly(ethylene glycol) (PAA-PEG) hybrid was synthesized. The factor of molecular weight of PEG in the hybrid plays an important role in determining the liquid electrolyte absorbency of the hybrid and ionic conductivity of the polymer gel electrolyte, sequentially affects the photovoltaic performance of quasi-solid-state dye-sensitized solar cells. Using the hybrid with PEG molecular weight of 20,000, a polymer gel electrolyte with liquid electrolyte absorbency of 6.9 g g−1 and ionic conductivity of 5.35 mS cm−1 was obtained. Based on the polymer gel electrolyte, a quasi-solid-state dye-sensitized solar cell with conversion efficiency of 5.25% was achieved under irradiation of AM 1.5, 100 mW cm−2.
Co-reporter:Yunfang Huang, Jihuai Wu, Yuelin Wei, Sancun Hao, Miaoliang Huang, Jianming Lin
Scripta Materialia 2007 Volume 57(Issue 5) pp:437-440
Publication Date(Web):September 2007
DOI:10.1016/j.scriptamat.2007.04.043
A series of photocatalytic intercalated materials K2−xLa2Ti3−xNbxO10 (0 ⩽ x ⩽ 1) and a series of its protonated derivatives H2−xLa2Ti3−xNbxO10 were prepared by solid-state reaction and ion-exchange reaction. The photocatalytic activities of samples were evaluated using methanol as electron donor under UV irradiation. All H2−xLa2Ti3−xNbxO10 samples possessed approximately twofold higher photocatalytic activity than the corresponding K2−xLa2Ti3−xNbxO10. This difference was most pronounced for the photocatalyst H1.9La2Ti2.9Nb0.1O10 which showed the highest activity: 22 μmol H2/catalyst (g) for 5 h, more than three times the activity of K1.9La2Ti2.9Nb0.1O10.
Co-reporter:Qunwei Tang;Jianming Lin;Jihuai Wu;Yuwen Xu;Chuanjuan Zhang
Journal of Applied Polymer Science 2007 Volume 104(Issue 2) pp:
Publication Date(Web):25 JAN 2007
DOI:10.1002/app.25531
A novel poly(acrylate-co-acrylamide)/expanded vermiculite (EVMT) superabsorbent composite was synthesized by aqueous solution polymerization method. The water absorbency of the superabsorbent composite still reaches 850 g/g when 50 wt % EVMT is added, which is significant in decreasing the production cost of the superabsorbent composites. By controlling the molar ratio of acrylic acid monomer and acrylamide monomer, and neutralization degree of acrylic acid, the hydrophilic groups on the composite can be adjusted, and it is found that the collaborative absorbent effect of CONH2, COOK, and COOH groups is superior to that of single CONH2, COOK, or COOH group. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 735–739, 2007
Co-reporter:Miaoliang Huang;Hongxun Yang;Jihuai Wu
Journal of Sol-Gel Science and Technology 2007 Volume 42( Issue 1) pp:65-70
Publication Date(Web):2007 April
DOI:10.1007/s10971-006-1510-x
Using poly(acrylonitrile-co-styrene) as polymer host, 1,2-propanediol carbonate, dimethyl carbonate and ethylene carbonate as mixture solvent, N-methyl-quinoline iodide and iodine as the source of I−/I3−, a novel polymer gel electrolyte with ionic conductivity of 5.12 × 10−3 S· cm−1 at 25°C was prepared by sol-gel and hydrothermal methods. Based on the polymer gel electrolyte, a quasi-solid-state dye-sensitized solar cell was fabricated. The solar cell possess better long-term stability and light-to-electrical energy conversion efficiency of 4.04% under irradiation of 100 mW· cm−2. The influences of polymer host, solvent, N-methyl-quinoline iodide and temperature on ionic conductivity of the polymer gel electrolyte and the performance of the dye-sensitized solar cell was discussed.
Co-reporter:JiHuai Wu;YingHan Cheng;JianMing Lin
Science China Chemistry 2007 Volume 50( Issue 4) pp:514-519
Publication Date(Web):2007 August
DOI:10.1007/s11426-007-0087-8
A novel photocatalytic material (Pt,Cd0.8Zn0.2S)/HLaNb2O7 was fabricated by successive intercalation and exchange reactions. The (Pt,Cd0.8Zn0.2S)/HLaNb2O7 possessed a gallery height less than 0.5 nm and showed a broad absorption with wavelength over 370–500 nm. Using (Pt,Cd0.8Zn0.2S)/HLaNb2O7 as catalyst, the photocatalytic H2 evolution was more than 160 cm3 · h−1 · g−1 in the presence of Na2S as a sacrificial agent under irradiation with wavelength more than 290 nm from a 100-W mercury lamp. Furthermore, the catalyst showed photocatalytic activity even under visible light irradiation.
Co-reporter:Jihuai Wu, Zhang Lan, Dongbo Wang, Sancun Hao, Jianming Lin, Yunfang Huang, Shu Yin, Tsugio Sato
Electrochimica Acta 2006 Volume 51(Issue 20) pp:4243-4249
Publication Date(Web):25 May 2006
DOI:10.1016/j.electacta.2005.11.047
A gel polymer electrolyte based on poly(acrylonitrile-co-styrene) as polymer matrix and N-methyl pyridine iodide salt as I− source was prepared. Controlling the concentration of polymer matrix of poly(acrylonitrile-co-styrene) at 17.5 wt.%, mixing the binary organic solvents mixture ethylene carbonate and propylene carbonate with 6:4 (w/w), and the concentration of N-methyl pyridine iodide and iodine with 0.5 and 0.05 M, respectively, the gel polymer electrolyte attains the maximum ionic conductivity (at 30 °C) of 4.63 mS cm−1. Based on the gel polymer electrolyte, a quasi-solid state dye-sensitized solar cell was fabricated and its overall energy conversion efficiency of light-to-electricity of 3.10% was achieved under irradiation of 100 mW cm−2.
Co-reporter:Jihuai Wu, Zhang Lan, Dongbo Wang, Sancun Hao, Jianming Lin, Yelin Wei, Shu Yin, Tsugio Sato
Journal of Photochemistry and Photobiology A: Chemistry 2006 Volume 181(2–3) pp:333-337
Publication Date(Web):31 July 2006
DOI:10.1016/j.jphotochem.2005.12.015
A novel gel polymer electrolyte based on poly(acrylamide)–poly(ethylene glycol) composite and binary organic solvent was prepared. And the highest ionic conductivity of the gel polymer electrolyte was 1.94 mS cm−1 under the ambient atmosphere. The polymer gel electrolyte based on the composite of poly(acrylamide)–poly(ethylene glycol), the binary organic solvent of ethylene carbonate and propylene carbonate and the additive of 4-tert-bytylpyridine has been employed to fabricate quasi-solid state dye-sensitized solar cell with an overall conversion efficiency of approximately 3% under irradiation of 60 mW cm−2.
Co-reporter:Jihuai Wu;Jinfeng Zhong;Jianming Lin;YueLin Wei;Yimin Xie
Polymer Engineering & Science 2006 Volume 46(Issue 3) pp:324-328
Publication Date(Web):27 JAN 2006
DOI:10.1002/pen.20483
Using partly neutralized acrylic acid as monomer, kaoline ultrafine powder as filler and N,N′-(dimethyl)acrylamide as crosslink agent, poly(sodium acrylate)/kaoline superabsorbent composite was synthesized by aqueous solution polymerization method. Using the superabsorbent composite as collagen, a hydrogel was prepared. The influence of the neutralization degree of superabsorbent collagen, the compositions, the concentration, and the pH value of exterior solution on the swelling behavior of the hydrogel was investigated. It was found that the swelling capability of the hydrogel depended on the groups on the collagen. The swelling capability of the hydrogel relied on the ionic intensity, molecular polarity, molecular volume, as well as the concentration of exterior solution. When the pH value of exterior solution was equal to seven, the hydrogel has a maximum swelling value of 800 times. POLYM. ENG. SCI. 46:324–328, 2006. © 2006 Society of Plastics Engineers
Co-reporter:Lingling Wang, Jihuai Wu, Miaoliang Huang, Jianming Lin
Scripta Materialia 2004 Volume 50(Issue 4) pp:465-469
Publication Date(Web):February 2004
DOI:10.1016/j.scriptamat.2003.10.033
HTaWO6/(Pt, Cd0.8Zn0.2S) was fabricated by successive intercalation reactions. The intercalation material shows a broad reflection over 300–580 nm and possess excellent photocatalytic capability under the irradiation of visible light. The photocatalytic activity of HTaWO6/Cd0.8Zn0.2S is superior to that of unsupported Cd0.8Zn0.2S and is enhanced by co-incorporation of Pt.
Co-reporter:Jihuai Wu;Yuelin Wei;Jianming Lin;Songbai Lin
Polymer International 2003 Volume 52(Issue 12) pp:
Publication Date(Web):21 OCT 2003
DOI:10.1002/pi.1303
A novel starch-graft-acrylamide/kaolinite superabsorbent composite with water absorbency 4000 times (g ) was synthesized by a graft copolymerization reaction among acrylamide, potato starch and kaolinite ultrafine powder, followed by saponification with NaOH. The influence of the hydrophilic group on water absorbency was investigated. It was found that the combined absorbent effect of —CONH2, —COONa and —COOH groups was superior to that of a single group, and the composite with the molar ratio of 8:6:3 for the —CONH2, —COONa and —COOH groups exhibits the highest water-absorbent ability. Copyright © 2003 Society of Chemical Industry
Co-reporter:Jihuai Wu, Jinling Huang, Naisheng Chen, Congrong Wei, Yike Chen
Journal of Materials Processing Technology 2003 Volume 137(1–3) pp:40-44
Publication Date(Web):30 June 2003
DOI:10.1016/S0924-0136(02)01064-6
Using quartz, talc and wollastonite as the initial minerals, silicone rubber reinforcement filler was prepared by ultra-fine crushing and surface chemical modifying with A-151 and B-5 coupling agent. The interaction between the silicone rubber matrix and the mineral filler was investigated from the aspects of the bound rubber in the uncured mix, the cross-linkage density in the relative vulcanite and the mechanical properties of the corresponding vulcanite. It was found that there are compact associations among the bound rubber in pure toluene, the total cross-linkage density and the tensile strength, and an association among the bound rubber in basic toluene, and the chemical cross-linkage density and modulus.
Co-reporter:Jihuai Wu;Changcang Huang;Chenghuang Xu;Jihuai Wu;Chenghuang Xu;Changcang Huang
Crystal Research and Technology 2003 Volume 38(Issue 12) pp:1052-1057
Publication Date(Web):6 NOV 2003
DOI:10.1002/crat.200310135
In order to adjust and broaden the absorption spectrum and emission spectrum of the (F2+)H type color center so as to match up to the pumping and to fit in with the demand of application, a (KBr-KCl)(OH−):(F2+)H color center laser crystal series was prepared by the process of single crystal growth, additive coloration, anneal, and light aggregation at 290 K and 77 K. The spectral characteristics of (KBr-KCl)(OH−) crystals are investigated. It is found that the absorption and emission band of the (F2+)H color centers in KBr-KCl complex host crystals has a considerable adjustment and extensions compared to the color centers in single KBr or KCl crystal. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Co-reporter:Jihuai Wu, Jianming Lin, Shu Yin and Tsugio Sato
Journal of Materials Chemistry A 2001 vol. 11(Issue 12) pp:3343-3347
Publication Date(Web):14 Sep 2001
DOI:10.1039/B103838A
HNbWO6/(Pt,Cd0.8Zn0.2S) nanocomposites have been fabricated by successive intercalation reactions of HNbWO6 with [Pt(NH3)4]Cl2 aqueous solution, with n-C3H7NH2/n-heptane mixed solution, and the Cd(MeCO2)2–Zn(MeCO2)2 mixture in aqueous solution, followed by the reaction between Cd2+–Zn2+ and H2S in the interlayer of HNbWO6. The gallery height of HNbWO6/CdS*, HNbWO6/Cd0.8Zn0.2S*, HNbWO6/CdS, HNbWO6/Cd0.8Zn0.2S, HNbWO6/(Pt, CdS) and HNbWO6/(Pt,Cd0.8Zn0.2S) is less than 0.5 nm in each case. HNbWO6/(Pt,Cd0.8Zn0.2S)
series nanocomposites show a broad reflectance over ca. 380–580 nm and are capable of efficient hydrogen evolution under the irradiation of visible light in the presence of Na2S as a sacrificial donor. The photocatalytic activities of HNbWO6/CdS and HNbWO6/Cd0.8Zn0.2S nanocomposites are superior to those of unsupported CdS and Cd0.8Zn0.2S and are enhanced by the the co-incorporation of Pt.
Co-reporter:Jianming Lin;Zhengfang Yang;Jihuai Wu;Minli Pu
Macromolecular Rapid Communications 2001 Volume 22(Issue 6) pp:422-424
Publication Date(Web):5 APR 2001
DOI:10.1002/1521-3927(20010301)22:6<422::AID-MARC422>3.0.CO;2-R
A novel poly(acrylic acid)/mica superabsorbent composite was synthesized by graft polymerization reaction between partially neutralized acrylic acid and ultrafine mica mineral powder. The water absorbency of the composite is higher than 1 100 g H2O/g. The influence of the neutralization degree of acrylic acid, as well as of the amounts of mica and crosslinker on the absorbing properties are discussed in this paper.
Co-reporter:Jihuai Wu;Jianming Lin;Guoqing Li;Congrong Wei
Polymer International 2001 Volume 50(Issue 9) pp:
Publication Date(Web):1 AUG 2001
DOI:10.1002/pi.728
A novel poly(acrylic acid)/montmorillonite superabsorbent composite with a water absorbency of 1100 times its own weight was synthesized by the graft copolymerization of acrylic acid with a cross-linking agent in the presence of montmorillonite ultrafine powder. The influence of the amount of crosslinker and montmorillonite on water absorbency has been investigated. It was found that a crosslinker concentration of 0.03 wt% and 30 wt% montmorillonite gave the best results. The collaborative absorbent effect of sodium carboxylate and carboxylic acid groups was superior to that of sodium carboxylate or carboxylic acid groups alone, and the composite with a ratio of about 2/3 for sodium carboxylate to carboxyl acid groups possessed the highest water absorbence.
© 2001 Society of Chemical Industry
Co-reporter:Jihuai Wu;Jianming Lin;Meng Zhou;Congrong Wei;Jianming Lin;Jihuai Wu;Meng Zhou;Congrong Wei
Macromolecular Rapid Communications 2000 Volume 21(Issue 15) pp:1032-1034
Publication Date(Web):19 OCT 2000
DOI:10.1002/1521-3927(20001001)21:15<1032::AID-MARC1032>3.0.CO;2-N
A novel starch-graft-polyacrylamide/clay superabsorbent composite is synthesized by graft copolymerization reaction of acrylamide, potato starch and clay mineral micropowder, followed by hydrolysis with sodium hydroxide. The water absorbency of the composite reaches 4 000 g H2O/g. The influence of kind and amounts of clay and of the crosslinker in the composite on the absorbent properties is discussed in this paper.
Co-reporter:Pinjiang Li, Jihuai Wu, Jianming Lin, Miaoliang Huang, Yunfang Huang, Qinghua Li
Solar Energy (June 2009) Volume 83(Issue 6) pp:845-849
Publication Date(Web):1 June 2009
DOI:10.1016/j.solener.2008.11.012
Pt/Carbon black counter electrode for dye-sensitized solar cells (DSSCs) was prepared by reducing H2PtCl6 with NaBH4 in carbon black. The Pt/Carbon black electrode had a high electrocatalytic activity for iodide/triiodide redox reaction. Using the Pt/Carbon black counter electrode, DSSC achieved 6.72% energy conversion efficiency under one sun illumination. Pt/Carbon black electrode shows the same energy conversion efficiency and lower cost compared with Pt electrode, which makes it available in DSSCs practical applications.
Co-reporter:Jianming Lin, Qunwei Tang, Jihuai Wu
Reactive and Functional Polymers (June 2007) Volume 67(Issue 6) pp:489-494
Publication Date(Web):June 2007
DOI:10.1016/j.reactfunctpolym.2007.02.002
Co-reporter:Jianming Lin, Qunwei Tang, Jihuai Wu, Sancun Hao
Reactive and Functional Polymers (April 2007) Volume 67(Issue 4) pp:
Publication Date(Web):1 April 2007
DOI:10.1016/j.reactfunctpolym.2007.01.011
A polyacrylate/graphite composite was synthesized by aqueous solution polymerization. Based on the electrical conductivity of graphite and the water absorbency of polyacrylate, a novel conductive hydrogel with a conductivity of 7.3 mS m−1 was prepared. The influence of crosslinker, initiator, monomer, neutralization degree, graphite, water absorbency and temperature on the electrical conductivity of the hydrogel was investigated. An appended network structure model of the polyacrylate/graphite conductive hydrogel is proposed.
Co-reporter:Jia Dong, Jihuai Wu, Jinbiao Jia, Jinhua Ge, Quanlin Bao, Chaotao Wang, Leqing Fan
Applied Surface Science (15 April 2017) Volume 401() pp:
Publication Date(Web):15 April 2017
DOI:10.1016/j.apsusc.2016.12.229
•Ni0.85Se was obtained by hydrothermal way and the film was gained by spin-coating.•Ni0.85Se film has good conductivity and excellent electrocatalytic activity.•DSSC based on transparent Ni0.85Se counter electrode obtains PCE of 8.96%.•The PCE reaches 10.76% when putting a mirror under Ni0.85Se counter electrode.Nickel selenide (Ni0.85Se) was synthesized by a facile one-step hydrothermal reaction and Ni0.85Se film was prepared by spin-coating Ni0.85Se ink on FTO and used as counter electrode (CE) in dye-sensitized solar cells (DSSC). The Ni0.85Se CEs not only show high transmittance in visible range, but also possess remarkable electrocatalytic activity toward I−/I3−. The electrocatalytic ability of Ni0.85Se films was verified by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization curves. The DSSC using Ni0.85Se CE exhibits a power conversion efficiency (PCE) of 8.96%, while the DSSC consisting of sputtered Pt CE only exhibits a PCE of 8.15%. When adding a mirror under Ni0.85Se CE, the resultant DSSC exhibits a PCE of 10.76%, which exceeds that of a DSSC based on sputtered Pt CE (8.44%) by 27.49%.
Co-reporter:Yongguang Tu, Jihuai Wu, Xin He, Panfeng Guo, Hui Luo, Quanzhen Liu, Jianming Lin, Miaoliang Huang, Yunfang Huang, Leqing Fan, Zhang Lan
Applied Surface Science (1 May 2017) Volume 403() pp:
Publication Date(Web):1 May 2017
DOI:10.1016/j.apsusc.2017.01.240
•The window period of the dropping process of anti-solvent is broaden.•The morphology and crystallization of perovskite films can be fine-adjusted.•The devices exhibit high reproducibility and PCE of the champion device is 17.84%.Lewis acid-base adduct approach with anti-solvent (diethyl ether) has been one of the efficient strategies to prepare high-quality perovskite films for top-performing perovskite solar cells. Conventionally, the molar ratio of CH3NH3I:PbI2:DMSO in the precursor solution is 1:1:1, however, DMSO will be volatile alongside the extraction of DMF due to its miscibility with DMF solvent during the process of anti-solvent washing, which introduces a non-stoichiometric intermediate adduct CH3NH3I·PbI2·xDMSO (x < 1). In this work, we increased the DMSO content in the Lewis acid-base adduct approach to enhance the conversion efficiency of perovskite solar cells. More complete intermediate adduct CH3NH3I·PbI2·DMSO and wider window period of washing process ensure high-quality perovskite films and high reproducibility with raised content of DMSO. Furthermore, the devices prepared by the precursor solution of CH3NH3I:PbI2:xDMSO (x = 2.0) exhibit high reproducibility and the best efficiency of perovskite solar cells is 17.84% under one-sun illumination.
Co-reporter:Qunwei Tang, Jihuai Wu, Xiaoming Sun, Qinghua Li, Jianming Lin and Miaoliang Huang
Chemical Communications 2009(Issue 16) pp:NaN2167-2167
Publication Date(Web):2009/02/23
DOI:10.1039/B821358E
By polymerization at 80 °C and crystal growth at 0 °C, highly oriented polyaniline flake and fiber arrays were self-assembled without any templates or surfactants.
Co-reporter:Yaoming Xiao, Jihuai Wu, Jeng-Yu Lin, Sheng-Yen Tai and Gentian Yue
Journal of Materials Chemistry A 2013 - vol. 1(Issue 4) pp:NaN1295-1295
Publication Date(Web):2012/11/05
DOI:10.1039/C2TA00073C
Because of the large specific surface area and superior electrical conductivity of multi-wall carbon nanotubes (MWCNTs) and the high electrocatalytic activity of cobalt sulfide (CoS), CoS/MWCNT hybrid films are deposited onto Ti foil substrates by sequential electrophoresis and pulse potentiostatic electrodeposition. Field-emission scanning electron microscopy observes that the surface of the MWCNTs is wrapped with a nano-honeycomb CoS thin film of ∼55 nm in thickness. Cyclic voltammograms, electrochemical impedance spectroscopy, and Tafel polarization characterization indicate that the CoS/MWCNT/Ti counter electrode (CE) has better electrocatalytic activity for I3− reduction than Pt CE. Under full sunlight illumination (100 mW cm−2, AM 1.5 G), the dye-sensitized solar cell based on the CoS/MWCNT/Ti CE achieves a power conversion efficiency of 8.05%, which exceeds that of the device based on Pt/Ti CE (6.39%).
Co-reporter:Gentian Yue, Jihuai Wu, Yaoming Xiao, Miaoliang Huang, Jianming Lin and Jeng-Yu Lin
Journal of Materials Chemistry A 2013 - vol. 1(Issue 4) pp:NaN1501-1501
Publication Date(Web):2012/11/19
DOI:10.1039/C2TA00860B
A high porous molybdenum sulfide–carbon (MoS2–C) hybrid film was prepared by using an in situ hydrothermal route. The MoS2–C hybrid film served as a low-cost and high efficient platinum-free counter electrode for a dye-sensitized solar cell (DSSC). The cyclic voltammetry, electrochemical impedance spectroscopy and Tafel curve analysis indicate that the MoS2–C electrode possesses low charge transfer resistance on the electrolyte–electrode interface, high electrocatalytic activity and fast reaction kinetics for the reduction of triiodide to iodide at the counter electrode, which is due to large specific surface area and special structure and compositions of MoS2–C film. A DSSC with the novel MoS2–C counter electrode achieve a high power conversion efficiency of 7.69% under standard light illumination, which exceeds that of the DSSC with a Pt counter electrode (6.74%).
Co-reporter:Yaoming Xiao, Jihuai Wu, Jengyu Lin, Gentian Yue, Jianming Lin, Miaoliang Huang, Yunfang Huang, Zhang Lan and Leqing Fan
Journal of Materials Chemistry A 2013 - vol. 1(Issue 44) pp:NaN13889-13889
Publication Date(Web):2013/09/12
DOI:10.1039/C3TA12972A
Multi-wall carbon nanotubes (MWCNTs) were deposited on a titanium (Ti) foil substrate by using electrophoresis, then a nano-corallines nickel sulfide (NiS) was deposited on the MWCNTs by using a pulse potentiostatic method. The high performance NiS/MWCNT/Ti hybrid film was firstly used as a Pt-free counter electrode (CE) in dye-sensitized solar cells (DSSCs). The surface of MWCNTs was wrapped with a nano-corallines NiS thin film of ∼45 nm in thickness. Under full sunlight illumination (100 mW cm−2, AM 1.5 G), DSSCs with a NiS/MWCNT/Ti CE achieved an enhanced photovoltaic conversion efficiency of 7.90%, while DSSCs with a Pt/Ti CE obtained the efficiency of 6.36%. The characterization of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) indicated that nano-corallines NiS had high electrocatalytic activity for I3− reduction, MWCNTs had high specific surface area and low resistance, and the synergistic effect of NiS and MWCNTs endowed the superior features of the hybrid film. Therefore, the NiS/MWCNT/Ti CE can be used as a promising alternative CE in low-cost and large-scale DSSCs.
Co-reporter:Zhang Lan, Jihuai Wu, Jianming Lin and Miaoliang Huang
Journal of Materials Chemistry A 2012 - vol. 22(Issue 9) pp:NaN3954-3954
Publication Date(Web):2012/01/25
DOI:10.1039/C2JM15019K
The thermal decomposition method is usually used for fabricating Pt counter electrodes for dye-sensitized solar cells (DSSCs). The limitation of the method is its little control over the Pt particle size, agglomeration of the Pt particles on the conductive substrate and poor uniformity of the Pt counter electrodes. Herein, homogeneously dispersed Pt particles on FTO conductive glasses were prepared with an improved thermal decomposition method through adding a small amount of polyvinyl pyrrolidone (PVP) in the Pt precursor solution. The different additional amounts of PVP in the Pt precursor solution could influence the morphologies of the Pt counter electrodes, which further influenced the catalytic activity of the Pt counter electrodes and the photovoltaic performance of DSSCs. An enhanced energy conversion efficiency of the DSSC of about 8.394% was obtained when the Pt counter electrode was prepared with the additional weight amount of PVP 3.5 times that of H2PtCl6·6H2O in the Pt precursor solution, obviously higher than the original 7.062% value of the DSSC with the Pt counter electrode prepared by the traditional unmodified thermal decomposition method on the same loaded low weight of 3.765 μg cm−2.
Co-reporter:Jihuai Wu, Haijun Yu, Leqing Fan, Genggeng Luo, Jianming Lin and Miaoliang Huang
Journal of Materials Chemistry A 2012 - vol. 22(Issue 36) pp:NaN19030-19030
Publication Date(Web):2012/08/02
DOI:10.1039/C2JM33856D
A redox intermedium p-phenylenediamine (PPD) with quick reversible faradaic processes is introduced into KOH electrolyte, referred to as pseudocapacitive effect occurring on the electrode/electrolyte surface. The KOH + PPD electrolyte as potential electrolyte for supercapacitors is investigated by UV-Vis spectroscopy and electrochemical methods. As expected, the supercapacitor with KOH + PPD electrolyte has a much higher electrode specific capacitance (605.225 F g−1) than the one with conventional KOH electrolyte (144.037 F g−1) at the same current density of 1 A g−1. Simultaneously, the supercapacitor with KOH + PPD electrolyte exhibits a much higher energy density (19.862 W h kg−1) than the supercapacitor with conventional KOH electrolyte (4.458 W h kg−1). Furthermore, the supercapacitor with KOH + PPD electrolyte shows superior charge–discharge stability. After 4000 cycles, its capacitive retention ratio is still as high as 94.530%.
Co-reporter:Qunwei Tang, Jihuai Wu, Yan Li, Jianming Lin, Ziying Tang and Miaoliang Huang
Journal of Materials Chemistry A 2011 - vol. 21(Issue 34) pp:NaN12934-12934
Publication Date(Web):2011/07/28
DOI:10.1039/C1JM12037A
Polyaniline (PANi) microtube arrays were synthesized by a secondary-template (fir wood and ZnO microtube array) method and confirmed by scanning electron microscopy (SEM). High magnification SEM observation revealed that the PANi microtube arrays were formed by nanospheres and nanorods. X-Ray diffraction, Fourier transform infrared spectroscopy and cyclic voltammetry were used to characterize the resultant PANi microtube arrays which were subsequently used as electrodes for glucose oxidase (GO) immobilization and the detection of glucose. Compared with the traditional PANi powder electrode, the bioelectrocatalytic activation of GO immobilized PANi microtube array electrode toward the oxidation of glucose has been significantly enhanced. The excellent properties, low cost, facile preparation and good biocompatibility of the PANi microtube arrays set a bridge between proteins/enzymes and electrodes, providing analytical access to a large group of enzymes for a variety of biosensor applications.
Co-reporter:Yongguang Tu, Jihuai Wu, Xin He, Panfeng Guo, Tongyue Wu, Hui Luo, Quanzhen Liu, Kai Wang, Jianming Lin, Miaoliang Huang, Yunfang Huang, Zhang Lan and Sizhong Li
Journal of Materials Chemistry A 2017 - vol. 5(Issue 9) pp:NaN4383-4383
Publication Date(Web):2017/01/24
DOI:10.1039/C6TA11004E
The organic–inorganic lead halide layer is a crucial factor in determining the photovoltaic performance of perovskite solar cells. Based on solvent engineering, we developed a three-step sequential coating method to prepare a high-quality CH3NH3PbI3 layer based on solvent (isopropanol) substitution. Stonehenge-like PbI2 nanostructures with controllable morphology and crystallinity were prepared by solvent substitution instead of the conventional annealing-treatment, affording several channels for CH3NH3I to penetrate into the PbI2 film due to volume expansion, and thus enabling the complete conversion from PbI2 to perovskite. In addition, the device exhibited high reproducibility by our method and achieved a high 17.78% power conversion efficiency under one-sun illumination. Furthermore, we optimized the production craft and successfully fabricated a uniform perovskite film (10 cm × 10 cm) via solvent substitution.
Co-reporter:Qunwei Tang, Yan Li, Ziying Tang, Jihuai Wu, Jianming Lin and Miaoliang Huang
Journal of Materials Chemistry A 2011 - vol. 21(Issue 40) pp:NaN16017-16017
Publication Date(Web):2011/09/13
DOI:10.1039/C1JM12952J
To elevate the operating temperature of proton exchange membranes (PEMs) to 200 °C under anhydrous conditions, in the current work, the protic ionic liquid, 1-methylimidazolium trifluoromethanesulfonate ([MIm][Tfo]), was used as an anhydrous proton conductor and integrated with a superabsorbent host polyacrylamide/polyethylene glycol interpenetrated polymer network (PAM/PEG IPN) by doping and adsorbing methods. The resultant membranes could be operated up to 200 °C under nonhumidified conditions, showing a proton conductivity of 17.02 and 10.37 mS cm−1 at 150 °C for [MIm][Tfo] doped and adsorbed PAM/PEG IPN membranes, respectively. Because of the intrinsic nature of the PAM/PEG IPN superabsorbent, the loaded [MIm][Tfo] could not leak from the PEM systems even under high temperatures and pressures. A percolation phenomenon was observed because of the formation of proton-conducting channels for proton transfer. The new PEM presented a maximum tensile strength of 12.4 MPa and elongation of 1068% and 10.0 MPa and 1594% for the membranes by doping and adsorbing methods, respectively. To increase the electrocatalytic activity and decrease the cost of the catalyst, we also developed a well-aligned low-Pt anode catalyst using a fir template, exhibiting high activity for methanol oxidation reaction. When the methanol gas was bubbled into [MIm][Tfo] around the anode catalyst parallel to its channels, the oxidation current density at 200 °C was 8.7 times larger than that at 25 °C, whereas it was 5.4 times larger at 200 °C than that at 25 °C perpendicular to its channels. The membranes and efficient catalysts are possible candidates for direct methanol fuel cells that operate at high temperature and anhydrous conditions. The use of superabsorbents opens up a new route to high-temperature PEMs.
Co-reporter:Qunwei Tang, Jihuai Wu, Ziying Tang, Yan Li, Jianming Lin and Miaoliang Huang
Journal of Materials Chemistry A 2011 - vol. 21(Issue 35) pp:NaN13364-13364
Publication Date(Web):2011/08/03
DOI:10.1039/C1JM11857A
Flexible and uniquely network-structured polyaniline (PANi) and polypyrrole (PPy) supported Pt and Ag catalysts were synthesized using eggshell membrane as a template and explored for the methanol oxidation reaction (MOR) for proton exchange membrane fuel cell (PEMFC) application. The scanning electron microscopy observation showed a hierarchically ordered macroporous network of PANi and PPy. Due to the difference of polymer and metal essences, Pt was in the form of nanoparticles and Ag was in the form of nanofibers on the surfaces of PANi and nanoflakes on PPy. Energy dispersive X-ray spectra, thermal gravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction patterns and X-ray photoelectron spectra were used to characterize the resultant catalysts. The results revealed that the prepared flexible catalysts had a Pt loading of 7.5 and 7.48 wt% in Pt/PANi and Pt/PPy, and a Ag loading of 11.3 and 5.78 wt% in Ag/PANi and Ag/PPy, respectively. The PANi network was in its crystalline structure, which was expected to provide very high conductivities and electrochemical properties. The cyclic voltammetric studies at room temperature showed an excellent electrocatalytic activity for MOR in acidic medium. The catalysts were also checked in the electro-oxidation of methanol at high temperatures, a much higher electrocatalytic activity at 200 °C than that at 50 °C and good stability made them potential candidates for high-temperature PEMFCs. Combined with the mechanical strength, it is believed that PANi-based catalysts are more useful in MOR applications. The excellent properties, alterable supports, simple preparation procedure and low cost allow these catalysts to be used in high-temperature PEMFCs and other fields.
Co-reporter:Guanglu Shang, Jihuai Wu, Shen Tang, Miaoliang Huang, Zhang Lan, Yan Li, Junchang Zhao and Xiaoping Zhang
Journal of Materials Chemistry A 2012 - vol. 22(Issue 48) pp:NaN25339-25339
Publication Date(Web):2012/10/16
DOI:10.1039/C2JM33897A
Three-dimensional hierarchical tin oxide microspheres (HM-SnO2) are successfully synthesized by hydrothermal treatment. The SnO2 microspheres with diameter of 1–4 μm are pure rutile phase and consist of nanosheets. The two-dimensional nanosheets ensure fast electron transport and slow charge carrier recombination. Due to their large particle size, the HM-SnO2 films can scatter light efficiently and enhance light harvesting. Because of the above advantages, a dye-sensitized solar cell (DSSC) based on the HM-SnO2 photoanode shows an energy conversion efficiency of 4.55%, which indicates a 12.6% improvement compared to the DSSC based on a current SnO2 nanoparticle photoanode prepared under the same conditions. Moreover, the photovoltaic performance of the DSSC can be improved by modifying the photoanode with a TiO2 blocking layer and TiCl4 post-treatment.
Co-reporter:Yaoming Xiao, Jeng-Yu Lin, Sheng-Yen Tai, Shu-Wei Chou, Gentian Yue and Jihuai Wu
Journal of Materials Chemistry A 2012 - vol. 22(Issue 37) pp:NaN19925-19925
Publication Date(Web):2012/08/03
DOI:10.1039/C2JM34425D
High performance poly(3,4-ethylenedioxythiophene) (PEDOT) nano-meadows were electropolymerized onto multi-wall carbon nanotube (MWCNT) as counter electrodes (CEs) for Pt-free dye-sensitized solar cells (DSCs) for the first time. This composite film was fabricated using an electrophoresis of MWCNTs onto a fluorinated tin oxide glass substrate and then subjected to PEDOT electropolymerization by using the pulse potentiostatic method. The surface of MWCNTs was wrapped with nano-meadows PEDOT thin film of ∼55 nm in thickness. The extensive cyclic voltammograms (CV) showed PEDOT/MWCNT CE with excellent electrocatalytic activity for I3− reduction. Moreover, the peak current densities of the PEDOT/MWCNT CE showed no sign of degradation after consecutive 200 CV tests, suggesting the great electrochemical stability of the PEDOT/MWCNT CE. The electrochemical impedance spectroscopy demonstrated that the PEDOT/MWCNT CE had the lowest charge-transfer resistance among all CEs tested in this study. The DSC assembled with the PEDOT/MWCNT composite CE demonstrated an enhanced photovoltaic conversion efficiency of 7.03% compared to that using conventional Pt CE (5.88%) under full sunlight illumination (100 mW cm−2, AM1.5 G) due to the intrinsic superior electrocatalytic activity of the nano-meadows PEDOT material, highly specific surface area and high electrical conductivity of the MWCNTs. Therefore, the PEDOT/MWCNT CE can be considered as a promising alternative CE for use in Pt-free DSCs.
Co-reporter:Qunwei Tang, Ziying Tang, Jihuai Wu, Jianming Lin and Ilkwon Oh
Journal of Materials Chemistry A 2011 - vol. 21(Issue 14) pp:NaN5385-5385
Publication Date(Web):2011/02/24
DOI:10.1039/C0JM04055J
This article reports a simple, versatile approach to the fabrication of high conducting multilayer films composed of alternating graphene (G) nanosheets and poly(sodium 4-styrenesulfonate) (PSS) using an electrostatic spin self-assembly technique. G nanosheets were prepared from natural graphite by oxidization, expansion, exfoliation, reduction and modification with cationic surfactant cetyltrimethylammonium bromide (C16TAB) and anionic surfactant sodium dodecyl sulfate (SDS). The growth process of the (PSS/G+/G−)n multilayer films was characterized by UV-vis spectroscopy. Absorbance plotted against the number of bilayers exhibited a linear dependence, indicating a progressive and uniform deposition process of the multilayer films. Higher rotation speeds (ω) can be used to fabricate thinner films, and the G content is in direct proportion to ω−1/2. The prepared (PSS/G+/G−)n multilayer films exhibit an attractive electrical conductivity in the range of 80–110 S cm−1. When the film thickness overcomes the effect of surface roughness and film morphology, a percolation effect is observed at the percolation threshold. The effects of the number of bilayers on the electrical properties of the ultrathin films are investigated in detail. The results show that the conductivity and percolation threshold can be controlled by adjusting the PSS/G+/G− ratio, rotation speed, and size of G nanosheets.
Co-reporter:Qunwei Tang, Jihuai Wu, Ziying Tang, Yan Li and Jianming Lin
Journal of Materials Chemistry A 2012 - vol. 22(Issue 31) pp:NaN15844-15844
Publication Date(Web):2012/05/17
DOI:10.1039/C2JM32637J
The development of high-temperature proton exchange membranes (HTPEMs) operated over 120 °C under anhydrous conditions is pursued worldwide in order to solve some core problems of current PEM fuel cells based on Nafion (CO tolerance, improved kinetics, water management, etc.). In the current work, two classes of HTPEMs based on absorbing and doping of the protic ionic liquid, 1-methylimidazolium trifluoromethanesulfonate ([MIm][Tfo]), into a 3D framework of poly(acrylic acid)–poly(ethylene glycol) (PAA–PEG) superabsorbent are successfully synthesized. The resultant membranes show high proton conductivity, good thermal stability and excellent mechanical strength due to the unique absorption property and interpenetrated polymer network of PAA–PEG, and good conduction of [MIm][Tfo]. Proton conductivities as high as 40.4 and 19.4 mS cm−1 at 200 °C under anhydrous conditions are obtained in [MIm][Tfo] doped and absorbed PAA–PEG membranes, respectively. The long-term stability of the superabsorbent-based membranes at high-temperatures, in combination with simple preparation, low cost, scalable host and proton conductor, demonstrates the potential use of these materials in HTPEMs.
Co-reporter:Guanglu Shang, Jihuai Wu, Miaoliang Huang, Zhang Lan, Jianming Lin, Qin Liu, Min Zheng, Jinghao Huo and Lu Liu
Journal of Materials Chemistry A 2013 - vol. 1(Issue 34) pp:NaN9874-9874
Publication Date(Web):2013/06/07
DOI:10.1039/C3TA11946G
Three-dimensional hierarchical titania bur-like microspheres (TiO2 BMs) composed of nanowires were synthesized by a hydrothermal method, and possess a specific surface area of 114 m2 g−1 and a main pore size of 6 nm. The one-dimensional nanowire ensures faster electron transport and a longer electron recombination time than titania nanoparticles (TiO2 NPs). Therefore, a film based on the TiO2 BMs exhibits excellent light scattering properties and thus enhances light harvesting efficiency. Using a TiO2 BM film as a scattering layer on the top of a compact TiO2 NP film, the double layered dye-sensitized solar cell (DSSC) shows a power conversion efficiency of 7.31%, indicating a 10.2% and 15.1% improvement compared to the DSSCs based on TiO2 NP and TiO2 BM single films, respectively.
Co-reporter:Yaoming Xiao, Gaoyi Han, Yanping Li, Miaoyu Li and Jihuai Wu
Journal of Materials Chemistry A 2014 - vol. 2(Issue 40) pp:NaN16862-16862
Publication Date(Web):2014/08/21
DOI:10.1039/C4TA03658A
Lead-doped TiO2 nanofibers (TNFs) are fabricated by using an electrospun method, followed by the in situ preparation of perovskite-sensitized photoanode for use in perovskite solar cells (PSC). The electrospun TNFs can provide direct pathways for the rapid collection and transmission of photogenerated electrons. The photoanode based on the in situ method shows not only excellent contacting between the TNF and perovskite, but also abundant perovskite filling in it. These can be conducive not only to the separation and transmission of the electron and hole, but also to the absorption and utilization of sunlight. Finally, a high performance PSC with the cell efficiency of 9.03% is obtained without any hole transporting materials.
Co-reporter:Le-Qing Fan, Ji Zhong, Ji-Huai Wu, Jian-Ming Lin and Yun-Fang Huang
Journal of Materials Chemistry A 2014 - vol. 2(Issue 24) pp:NaN9014-9014
Publication Date(Web):2014/04/23
DOI:10.1039/C4TA01408A
A redox-active gel polymer electrolyte was prepared by introducing KI/VOSO4 redox additives into a polyvinyl alcohol–H2SO4 gel electrolyte for application in a quasi-solid-state electric double-layer capacitor (EDLC) based on activated carbon. The EDLC obtained had a high electrode-specific capacitance of 1232.8 F g−1 and a high energy density of 25.4 W h kg−1; these values are higher than that of an EDLC with a conventional gel electrolyte. The improved energy storage is attributed to Faradaic pseudocapacitance related to the redox-active ions in the gel polymer electrolyte.
Co-reporter:Geng-Geng Luo, Kai Fang, Ji-Huai Wu and Jun Mo
Chemical Communications 2015 - vol. 51(Issue 62) pp:NaN12364-12364
Publication Date(Web):2015/06/26
DOI:10.1039/C5CC03897A
A noble-metal-free molecular dyad was constructed by anchoring a thienyl-expanded BODIPY photosensitizer (PS) to a cobaloxime catalyst, which gives a 2.5-fold increase in the TON, and a 3-fold enhancement in the quantum efficiency as compared to the multicomponent catalytic system for the generation of hydrogen via the reduction of water. The stability of PS was expected to improve by introducing the thienyl moiety into the BODIPY core.
]chloro(pyridine)-, (OC-6-42)-](http://img.cochemist.com/ccimg/23300/23295-32-1.png)
]chloro(pyridine)-, (OC-6-42)-](http://img.cochemist.com/ccimg/23300/23295-32-1_b.png)
