Co-reporter:Jing Qin, Jiangna Guo, Qiming Xu, Zhiqiang Zheng, Hailei Mao, and Feng Yan
ACS Applied Materials & Interfaces March 29, 2017 Volume 9(Issue 12) pp:10504-10504
Publication Date(Web):March 8, 2017
DOI:10.1021/acsami.7b00387
Pyrrolidinium-type small molecule ionic liquids (ILs), poly(ionic liquid) (PIL) homopolymers, and their corresponding PIL membranes were synthesized and used for antibacterial applications. The influences of substitutions at the N position of pyrrolidinium cation on the antimicrobial activities against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were studied by minimum inhibitory concentration (MIC). The antibacterial efficiency of both the small molecule ILs and PIL homopolymers increased with the increase of the alkyl chain length of substitutions. Furthermore, PIL homopolymers show relatively lower MIC values, indicating better antimicrobial activities than those of the corresponding small molecule ILs. However, the antibacterial properties of the PIL membranes are contrary to corresponding ILs and PIL homopolymers, which reduce with the increase of alkyl chain length. Furthermore, the resultant PIL membranes show excellent hemocompatibility and low cytotoxicity toward human cells, demonstrating clinical feasibility in topical applications.Keywords: antibacterial materials; cytotoxicity; poly(ionic liquid)s; polymer membranes; pyrrolidinium cations;
Co-reporter:Zhenyong Wang;Lei Wang;Ye Zhang;Jiangna Guo;Hao Li
RSC Advances (2011-Present) 2017 vol. 7(Issue 23) pp:13689-13695
Publication Date(Web):2017/02/28
DOI:10.1039/C6RA26402F
An imidazolium-based co-containing room temperature ionic liquid, bis(3-butyl-1-methylimidazolium) tetraisothiocyanato cobalt [BMI]2[Co(NCS)4], was synthesized and characterized. The prepared [BMI]2[Co(NCS)4]/1-propyl-3-methylimidazolium iodine (PMII) hybrid redox couple showed higher redox potential than that of the iodide/triiodide (I−/I3−) redox couple. The resultant dye-sensitized solar cells (DSSCs) containing the [BMI]2[Co(NCS)4]/PMII hybrid redox couple exhibited an average overall power conversion efficiency of 8.1% under simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2, which is higher than that of traditional PMII/I2 based electrolytes probably due to the enhancement of the Voc values of the hybrid electrolytes. Furthermore, the cell based on the [BMI]2[Co(NCS)4]/PMII hybrid redox couple tested in this study showed excellent long-term stability under ambient conditions over 120 days.
Co-reporter:Cancan Wang;Winston Duo Wu;Ying Wang;Dan Xu
New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 15) pp:7392-7399
Publication Date(Web):2017/07/24
DOI:10.1039/C7NJ01178D
A strategy for the rational design and synthesis of nitrogen doped carbon as an efficient cathode catalyst for the oxygen reduction reaction (ORR) is developed. A high performance catalyst is obtained directly by carbonization of a bicomponent mixture containing Gentiana scabra Bunge (nature provided biomass) and ammonium chloride (NH4Cl), which are easily available and inexpensive. Gentiana scabra Bunge functions as a carbon source, while ammonium chloride acts as both a nitrogen dopant and a porogen. Furthermore, synergistically tailoring the NH4Cl/Gentiana scabra Bunge feed ratio and the carbonization temperature makes the chemical and physical properties of the as-prepared carbon controllable and thus helps in realising ORR-performance-oriented design and synthesis of nitrogen doped carbon. The synthesized porous carbon (specific surface area of up to 1440 m2 g−1 and 14 wt% nitrogen content) is an ideal material in the ORR that requires high specific surface area, easy accessibility to the active sites through the hierarchical porous system and excellent electrical conductivity. Therefore, the synthesized porous carbon shows high ORR activity with comparable performance to a Pt/C catalyst in both acidic and alkaline solutions, allowing large scale production of carbon materials for practical application in fuel cells.
Co-reporter:Fei Chen;Yongyuan Ren;Jiangna Guo
Chemical Communications 2017 vol. 53(Issue 10) pp:1595-1598
Publication Date(Web):2017/01/31
DOI:10.1039/C6CC08924K
Thermo- and electro-dual responsive poly(ionic liquid) (PIL) based electrolytes were synthesized by co-polymerization of N-isopropylacrylamide (NIPAM) with (or without) 3-butyl-1-vinyl-imidazolium bromide ([BVIm][Br]) using diallyl-viologen (DAV) as both the cross-linking agent and electrochromic material.
Co-reporter:Wenjing Qian;John Texter
Chemical Society Reviews 2017 vol. 46(Issue 4) pp:1124-1159
Publication Date(Web):2017/02/20
DOI:10.1039/C6CS00620E
We review recent works on the synthesis and application of poly(ionic liquid)s (PILs). Novel chemical structures, different synthetic strategies and controllable morphologies are introduced as a supplement to PIL systems already reported. The primary properties determining applications, such as ionic conductivity, aqueous solubility, thermodynamic stability and electrochemical/chemical durability, are discussed. Furthermore, the near-term applications of PILs in multiple fields, such as their use in electrochemical energy materials, stimuli-responsive materials, carbon materials, and antimicrobial materials, in catalysis, in sensors, in absorption and in separation materials, as well as several special-interest applications, are described in detail. We also discuss the limitations of PIL applications, efforts to improve PIL physics, and likely future developments.
Co-reporter:Qi Li, Dan Xu, Jiangna Guo, Xu Ou, Feng Yan
Carbon 2017 Volume 124(Volume 124) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.carbon.2017.09.029
Preparation of high-performance carbon materials with an abundance of heteroatoms, edges, and defects for sustainable energy-conversion technologies, such as supercapacitors and oxygen reaction reduction (ORR), are still a challenge. Herein, we reported a facile strategy for the large-scale synthesis of nitrogen-doped porous carbon via carbonization of core-shell structured protonated g-C3N4@polypyrrole (P-g-C3N4@PPy) nanocomposites. Polypyrrole provided both the carbon and heteroatom sources, while P-g-C3N4 acted not only as a sacrificial template but also as nitrogen sources. Porous carbon derived from P-g-C3N4@PPy (denoted as PCN@PPy-C-900) exhibited a specific capacitance of 350 F g−1 at a current density of 5 A g−1 and a high-rate capability (320 F g−1) at 20 A g−1 in 6 M KOH aqueous solution, as well as good long-term stability after 1000 cycles. In addition, PCN@PPy-C-900 also displayed excellent electrocatalytic performances in ORR in 0.1 M KOH aqueous solution. The excellent electrochemical performances provide guidance for the structure design of this promising class of multifunctional carbon-based materials which can be large scale applied to supercapacitors, ORR, and other fields.Download high-res image (324KB)Download full-size image
Co-reporter:Zhiqiang Zheng, Qiming Xu, Jiangna Guo, Jing Qin, Hailei Mao, Bin Wang, and Feng Yan
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 20) pp:12684-12692
Publication Date(Web):May 4, 2016
DOI:10.1021/acsami.6b03391
The structure–antibacterial activity relationship between the small molecular compounds and polymers are still elusive. Here, imidazolium-type ionic liquid (IL) monomers and their corresponding poly(ionic liquids) (PILs) and poly(ionic liquid) membranes were synthesized. The effect of chemical structure, including carbon chain length of substitution at the N3 position and charge density of cations (mono- or bis-imidazolium) on the antimicrobial activities against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was investigated by determination of minimum inhibitory concentration (MIC). The antibacterial activities of both ILs and PILs were improved with the increase of the alkyl chain length and higher charge density (bis-cations) of imidazolium cations. Moreover, PILs exhibited lower MIC values relative to the IL monomers. However, the antibacterial activities of PIL membranes showed no correlation to those of their analogous small molecule IL monomers and PILs, which increased with the charge density (bis-cations) while decreasing with the increase of alkyl chain length. The results indicated that antibacterial property studies on small molecules and homopolymers may not provide a solid basis for evaluating that in corresponding polymer membranes.
Co-reporter:Jinyu Zhang, Dan Xu, Wenjing Qian, Jingyue Zhu, Feng Yan
Carbon 2016 Volume 105() pp:183-190
Publication Date(Web):August 2016
DOI:10.1016/j.carbon.2016.04.034
A facile and efficient strategy for the synthesis of heteroatom-doped carbon materials was developed, in which host–guest inclusion complexes were employed as versatile precursors. Inclusion of heteroatom containing guest molecules in the cavity of host molecules (such as cyclodextrins and cucurbit[n]urils) not only doped the carbon frameworks with heteroatoms (for instance, nitrogen, sulfur, boron, fluorine and iron), but also highly improved the carbonization yield. Since the chemical structure (composition) of host–guest inclusion complexes can be finely tuned at molecular level, they are ideal small molecular precursors for heteroatoms doped carbon materials. A nitrogen-doped porous carbon material derived from inclusion complexes exhibited a high performance as supercapacitors electrode with a high specific capacitance (348 F g−1) at a current density of 1 A g−1 in 6 M KOH aqueous solution and good cycling stability over 5000 cycles, demonstrating its potential application in energy storage.Host–guest inclusion complexes-derived heteroatom-doped carbon materials were prepared and employed for high-performance supercapacitor electrode materials.
Co-reporter:Fei Chen, Jiangna Guo, Dan Xu and Feng Yan
Polymer Chemistry 2016 vol. 7(Issue 6) pp:1330-1336
Publication Date(Web):06 Jan 2016
DOI:10.1039/C5PY01927C
Thermo- and pH-responsive poly(ionic liquid) (PIL) membranes were synthesized via photo-crosslinking of imidazolium type IL monomers with acrylic acid (AA), N-isopropylacrylamide (NIPAM), and acrylonitrile (AN). The transmittance of the prepared PIL membranes was determined by the concentration of AA units and the hydrophobicity of PIL counter anions, and could be altered in response to temperature and (or) pH. The shape deformation of the PIL membranes can be reversibly tuned by changing the pH value of aqueous solutions or gas atmospheres (NH3/HCl). The dual-responsive PIL membranes prepared in this work can act as a soft actuator, and would have potential applications in advanced sensors and functional materials for inscription of information.
Co-reporter:Jing Zhang;Dan Xu;Jiangna Guo;Zhe Sun;Wenjing Qian;Ye Zhang
Macromolecular Rapid Communications 2016 Volume 37( Issue 14) pp:1194-1199
Publication Date(Web):
DOI:10.1002/marc.201600069
Co-reporter:Ye Zhang, Zhe Sun, Chengzhen Shi and Feng Yan
RSC Advances 2016 vol. 6(Issue 74) pp:70460-70467
Publication Date(Web):20 Jul 2016
DOI:10.1039/C6RA11592F
An imidazolium thiopropionate-based redox couple is introduced as an improved organic alternative to iodide/triiodide (I−/I3−) couples for dye-sensitized solar cells (DSSCs). The synthesized thiolate/disulfide (BMIT/BMIDT) redox couple shows negligible absorption in the visible spectral range, and higher redox potential (+0.72 V vs. NHE) compared with that of I−/I3−. With the optimized redox couple (such as 0.1 M/0.1 M)/dye N719 formulation, the fabricated DSSCs exhibit an average overall power conversion efficiency (PCE) of 6.8% and 8.1% under the simulated air mass 1.5 solar spectrum illumination at 100 and 50 mW cm−2, respectively. However, a higher concentration of the BMIT/BMIDT redox couple (such as 0.4 M/0.4 M) decreases the PCE of the devices, due to the desorption of dye molecules from the TiO2 photoelectrode surface.
Co-reporter:Hao Li, Shichao Li, Ye Zhang and Feng Yan
RSC Advances 2016 vol. 6(Issue 1) pp:346-352
Publication Date(Web):16 Dec 2015
DOI:10.1039/C5RA22324E
TiO2 photoelectrodes with channels (or pores) are prepared by using an inorganic salt (NaHCO3) as a template. NaHCO3 doped TiO2 slurries deposited on a compacted TiO2 film are heated at 150 °C, which releases CO2 gas and water vapour, thus forming channels (or pores) inside a TiO2 light-scattering photoelectrode. These channels (pores) improve the penetration degree of solid-state electrolytes into the TiO2 photoelectrode and enhance the photovoltaic efficiency of resulting DSSCs (dye sensitized solar cells). With a channel (pore) size of ∼500 nm diameter, an ionic liquid plastic crystal, 5-azoniaspiro[4.4]nonane bis(trifluoromethanesulfonyl)imide (N44TFSI), shows power conversion efficiencies of 6.1% and 5.4% under 1.5 solar spectrum illuminations at 50 and 100 mW cm−2, respectively.
Co-reporter:Ye Zhang;Zhe Sun; Si Cheng; Feng Yan
ChemSusChem 2016 Volume 9( Issue 8) pp:813-819
Publication Date(Web):
DOI:10.1002/cssc.201600110
Abstract
The efficiency of dye-sensitized solar cells (DSSCs) is generally limited by the mismatch between the absorption spectrum of the photosensitizer and the solar irradiation spectrum. This work describes the use of a mixture that containing proper proportions of SiO2 coated Au nanospheres (AuNSs@SiO2) and Au nanorods (AuNRs@SiO2) (the mixture was denoted as AuNCs@SiO2) to enhance the sunlight utility in DSSCs. The incorporation of AuNCs@SiO2 into the TiO2 photoanode induced broadband light-harvesting at both low- and long- wavelengths and thus enhanced the photocurrent compared to that of plasmonic solar cells based on either AuNSs@SiO2 or AuNRs@SiO2. Upon the doping of AuNCs@SiO2, the overall power conversion efficiency (PCE) increased from 7.39 to 9.12 % for DSSCs based on organic liquid electrolytes.
Co-reporter:Chao Yuan, Jiangna Guo, Zhihong Si and Feng Yan
Polymer Chemistry 2015 vol. 6(Issue 22) pp:4059-4066
Publication Date(Web):17 Apr 2015
DOI:10.1039/C5PY00423C
Microemulsions are thermodynamically stable solutions comprising of two immiscible liquids, and at least one additional component, typically a surfactant. The use of microemulsions as templates for the synthesis of nanostructured polymer materials has been well developed. Ionic liquid-based microemulsions have recently attracted a great deal of interest because of their unique features attributable to ionic liquids. This review summarizes recent studies of polymerizations in IL-based microemulsions, and some applications for the synthesis of polymeric materials.
Co-reporter:Jiangna Guo, Qiming Xu, Zhiqiang Zheng, Shengbo Zhou, Hailei Mao, Bin Wang, and Feng Yan
ACS Macro Letters 2015 Volume 4(Issue 10) pp:1094
Publication Date(Web):September 15, 2015
DOI:10.1021/acsmacrolett.5b00609
The development of materials with intrinsically antimicrobial activities has attracted great interest. Herein, we report the synthesis of free-standing and robust poly(ionic liquid) (PIL) membranes with high antibacterial activities by in situ photo-cross-linking of an ionic liquid monomer and followed by anion-exchange with an amino acid (l-proline (Pro) or l-tryptophan (Trp)). The resultant PIL-based membranes with excellent robustness exhibit high antimicrobial properties against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) and present no significant hemolysis and cytotoxicity toward human red blood and skin fibroblast cells, as well as low adsorption of bovine serum albumin. The synthesized PIL-Trp membranes exhibit the highest antibacterial efficiency due to the synergistic attributes of both imidazolium cation and Trp– anion. Furthermore, all the PIL-based membranes exhibit long-term antibacterial stability, which demonstrates clinical feasibility in topical applications.
Co-reporter:Jing Zhang, Wei Zhang, Jiangna Guo, Chao Yuan, Feng Yan
Electrochimica Acta 2015 Volume 165() pp:98-104
Publication Date(Web):20 May 2015
DOI:10.1016/j.electacta.2015.02.244
•We prepare high ionic liquid content (up to 97 wt%) supramolecular ionogels.•The prepared supramolecular ionogels could be applied as quasi-solid-state electrolyte dye-sensitized solar cells.•The dye-sensitized solar cells achieve an efficiency of 4.62%.High ionic liquid content (up to 97 wt%) supramolecular ionogels are prepared via host-guest interactions between a host of β-cyclodextrin (β-CD) and a guest of bis-imidazolium ionic liquid, Bis-C12(mim)Br, in a room temperature ionic liquid, 1-propyl-3-methylimidazolium iodide (PMII). The driving force for the formation of supramolecular ionogels is attributed to the intermolecular hydrogen bonding of imidazolium cations. The ionic conductivity and gel-to-sol phase transition temperature of the prepared supramolecular ionogels can be tuned by the ratio of Bis-C12(mim)Br (guest) to β-CD (host), as well as the content of PMII solvent. The prepared supramolecular ionogels are applied as quasi-solid-state electrolytes for dye-sensitized solar cells (DSSCs), which show an efficiency of 4.62% under a simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2 and excellent long-term stability.Ultrahigh ionic liquid content supramolecular ionogels were prepared via host-guest interactions and was further employed to fabricate quasi-solid-state DSSCs.
Co-reporter:Jiangna Guo;Jie Zhao;Bin Wang
Journal of Polymer Science Part A: Polymer Chemistry 2015 Volume 53( Issue 13) pp:1600-1605
Publication Date(Web):
DOI:10.1002/pola.27595
ABSTRACT
Water-soluble cationic polypyrrole, poly(N-(4-butyl-(1-methylimidazole)) pyrrole bromide) (PNBMIP-Br), was synthesized and applied for base pair mismatched oligonucleotides detection. Interactions between PNBMIP-Br and a series of oligonucleotides, including ss-DNA and base pair mismatched ds-DNA were studied by fluorometric spectra, circular dichroism spectra and voltammetric detection. The results showed that the electrostatic attraction and fluorescence resonance energy transfer of PNBMIP-Br/DNA complexes resulted in an amplification and effective recognition of the fluorescence signals. The results of cyclic voltammograms indicate that voltammetric detection is an effective method to distinguish ss-DNA and ds-DNA. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1600–1605
Co-reporter:Wenjing Qian, Fengxia Sun, Yanhui Xu, Lihua Qiu, Changhai Liu, Suidong Wang and Feng Yan
Energy & Environmental Science 2014 vol. 7(Issue 1) pp:379-386
Publication Date(Web):12 Nov 2013
DOI:10.1039/C3EE43111H
Heteroatom doped porous carbon flakes were prepared via carbonization of Chinese human hair fibers and employed for high-performance supercapacitor electrode materials. The morphology and chemical composition of the resultant carbon materials were characterized by electron microscopy (EM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) measurements. Human hair carbonized at 800 °C exhibited high charge storage capacity with a specific capacitance of 340 F g−1 in 6 M KOH at a current density of 1 A g−1 and good stability over 20000 cycles. The specific capacitance of 126 F g−1 is also verified in a 1 M LiPF6 ethylene carbonate/diethyl carbonate (EC/DEC) organic electrolyte at a current density of 1 A g−1. The high supercapacitor performance could be due to the micro/mesoporosity combined with high effective surface area and heteroatom doping effects, combining double layer and Faradaic contributions.
Co-reporter:Shichao Li;Lihua Qiu;Chengzhen Shi;Xiaojian Chen
Advanced Materials 2014 Volume 26( Issue 8) pp:1266-1271
Publication Date(Web):
DOI:10.1002/adma.201304000
Co-reporter:Jiangna Guo, Chao Yuan, Mingyu Guo, Lei Wang and Feng Yan
Chemical Science 2014 vol. 5(Issue 8) pp:3261-3266
Publication Date(Web):28 Apr 2014
DOI:10.1039/C4SC00864B
A robust and flexible polymer velcro was synthesized via surface modification of poly(ionic liquid) (PIL) membranes with ferrocene (Fc) and β-cyclodextrin (β-CD) moieties, which act as the hooks and loops, respectively. Through molecular recognition between the β-CD and Fc moieties, the prepared PIL-β-CD and PIL-Fc membranes adhered with each other under mechanical compression, without the use of any curing agents. This polymer velcro exhibits strong adhesion in air and in aqueous solutions (including acidic and basic water, and artificial seawater), and could be unfastened and fastened by mechanical and chemical means. Due to the intrinsic ionic conductivity of the PIL membranes, our polymer velcro possesses an unprecedented feature, that the adhesion reversibility can be electrochemically controlled by the applied potential.
Co-reporter:Dan Xu, Chengzhen Shi, Lei Wang, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2014 vol. 2(Issue 25) pp:9803-9811
Publication Date(Web):22 Apr 2014
DOI:10.1039/C4TA01255K
The charge recombination at the TiO2 photoelectrode/electrolyte interface plays a crucial role in determining the efficiency of solid-state dye-sensitized solar cells (DSSCs) because of the poor interface contact at the TiO2 photoelectrode/electrolyte interface. In this work, we report the surface co-grafting of surfactants onto the surface of the TiO2 photoelectrode, and their effects on the photovoltaic performance of solid-state DSSCs. Three ionic surfactants, including anionic surfactants, sodium 2-ethylhexyl sulfosuccinate (AOT) and chenodeoxycholic acid (CDCA), and a cationic surfactant, dodecyltrimethylammonium bromide (DTAB), were applied for the modification of the TiO2 photoelectrode/electrolyte interface. The results show that co-grafting of surfactants AOT or CDCA on the TiO2 photoelectrode surface, and post heat treatment (above the melting point of solid-state electrolytes) could drastically improve the interfacial contact properties of the TiO2 photoelectrode/electrolyte interface, increase the penetration of the electrolytes into the porous TiO2 photoelectrode, and thus enhance the photovoltaic performances of the solid-state electrolyte DSSCs. With the surface modification of AOT/N719, the succinonitrile based solid-state DSSCs exhibited superior long-term stability, and showed power conversion efficiencies of 6.75% and 7.92% under 1.5 solar spectrum illuminations at 100 and 50 mW cm−2, respectively.
Co-reporter:Zhihong Si, Zhe Sun, Fenglou Gu, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2014 vol. 2(Issue 12) pp:4413-4421
Publication Date(Web):06 Jan 2014
DOI:10.1039/C3TA15178F
Solvent processable anion exchange membranes (AEMs) containing imidazolium cation and poly(arylene ether sulfone) side chains were prepared via the ionization of poly(4-vinylbenzyl chloride)-graft-poly(arylene ether sulfone) copolymers, and followed by anion exchange with hydroxide ions. The ionized copolymers produced ductile, transparent membranes which possess a relatively high ionic conductivity (up to 1.6 × 10−2 S cm−1 at room temperature). The yielded membranes are soluble in polar aprotic solvents, such as DMSO and DMF, while insoluble in water and methanol. The synthesized AEMs show good alkaline stability in 1 M KOH at 60 °C for 20 days, as well as high dimensional and thermal stability. These results should pave way to the practical application of this kind of AEM in alkaline fuel cells.
Co-reporter:Haigang Zhang, Lihua Qiu, Dan Xu, Wei Zhang and Feng Yan
Journal of Materials Chemistry A 2014 vol. 2(Issue 7) pp:2221-2226
Publication Date(Web):29 Nov 2013
DOI:10.1039/C3TA14571A
Liquid electrolyte DSSCs using 100% water as the solvent and I−/I3− as the redox couple were fabricated. The effect of ionic surfactants on water based DSSCs was investigated by electrochemical impedance spectroscopy (EIS) and contact angle measurements. Addition of surfactant to the aqueous electrolyte improved the interfacial contact between the aqueous electrolyte and the TiO2 films while decreased the interface recombination resistance. With the addition of 0.2 wt% of N,N,N-trimethyl-3-(perfluorooctylsulfonamido)propan-1-aminium iodide (FC-134) in the aqueous electrolyte, average overall power conversion efficiencies of 3.96% and 4.66% were obtained under the simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2 and 50 mW cm−2, respectively. These results show a feasible scheme towards the fabrication of greener and more efficient aqueous DSSCs.
Co-reporter:Zhihong Si, Lihua Qiu, Huilong Dong, Fenglou Gu, Youyong Li, and Feng Yan
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 6) pp:4346
Publication Date(Web):February 26, 2014
DOI:10.1021/am500022c
Imidazolium cations with butyl groups at various substitution positions (N1-, C2-, and N3-), 1-butyl-2,3-dimethylimidazolium ([N1-BDMIm]+), 2-butyl-1,3-dimethylimidazolium ([C2-BDMIm]+), and 3-butyl-1,2-dimethylimidazolium ([N3-BDMIm]+), were synthesized. Quantitative 1H NMR spectra and density functional theory calculation were applied to investigate the chemical stability of the imidazolium cations in alkaline solutions. The results suggested that the alkaline stability of the imidazolium cations was drastically affected by the C2-substitution groups. The alkaline stability of imidazolium cations with various substitution groups at the C2-position, including 2-ethyl-1-butyl-3-methylimidazolium ([C2-EBMIm]+), 1,2-dibutyl-3-methylimidazolium ([C2-BBMIm]+), and 2-hydroxymethyl-1-butyl-3-methylimidazolium ([C2-HMBMIm]+), was further studied. The butyl group substituted imidazolium cation ([C2-BBMIm]+) exhibited the highest alkaline stability at the elevated temperatures. The synthesized anion-exchange membranes based on the [C2-BBMIm]+ cation showed promising alkaline stability. These observations should pave the way to the practical application of imidazolium-based anion exchange membrane fuel cells.Keywords: alkaline stability; anion exchange membranes; imidazolium cations; substitution; theory calculation;
Co-reporter:Wei Zhang, Chao Yuan, Jiangna Guo, Lihua Qiu, and Feng Yan
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 11) pp:8723
Publication Date(Web):April 29, 2014
DOI:10.1021/am501523x
A 1-propyl-3-methylimidazolium iodide based supramolecular ionic liquid gel was prepared through the host–guest interactions between a host of β-cyclodextrin and a room temperature ionic liquid type guest, 1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide, which contains bis(trifluoromethylsulfonyl)imide as the guest group. The gel-to-sol phase transition temperature of the prepared supramolecular ionic liquid gel could be tuned by the ratio of host to guest. The synthesized supramolecular ionic liquid gel was further applied in quasi-solid-state electrolyte dye-sensitized solar cells, which showed a power conversion efficiency of 4.79% under the simulated air mass 1.5 solar spectrum illumination at 100 mW cm–2 and excellent long-term stability.Keywords: dye-sensitized solar cells; host−guest; ionic liquid; supramolecular gel; β-cyclodextrin;
Co-reporter:Chao Yuan, Jiangna Guo, Mei Tan, Mingyu Guo, Lihua Qiu, and Feng Yan
ACS Macro Letters 2014 Volume 3(Issue 3) pp:271
Publication Date(Web):March 3, 2014
DOI:10.1021/mz500113n
Electroactive supramolecular gels with multistimuli responsiveness were fabricated through host–guest interactions between a host polymer containing β-cyclodextrin (CD) and an ionic liquid (IL) type asymmetric gemini guest, which contains both ferrocene (Fc) and bis(trifluoromethyl-sulfonyl)imide (TFSI–) as the respective α- and ω-guest groups. Owing to the multiple stimuli-responsiveness of the host–guest interactions, reversible sol–gel phase transition could be triggered by various stimuli, including temperature, electrochemical/chemical redox and anion-exchange reactions. Due to the intrinsically conductive properties of the IL gemini guest, the sol–gel transition behavior could be electrochemically controlled by the applied voltage, without using additional supporting electrolyte.
Co-reporter:Lei Wang, Lihua Qiu, Zhenzhong Yang, Feng Yan
Electrochimica Acta 2014 Volume 133() pp:446-452
Publication Date(Web):1 July 2014
DOI:10.1016/j.electacta.2014.04.124
•Polymeric nanotubes were synthesized and used as gelators in DSSCs.•The polymeric nanotube as low as 1 wt% dose could form the IL gel electrolyte.•The gel electrolytes exhibit an efficiency of 4.9%.•The gel electrolytes show good long-term stability.Poly(divinybenzene-co-chloromethylstyrene) (poly(DVB-co-VBC)) nanotubes (PDVBVBC-NT) and imidazolium surface functionalized poly(DVB-co-VBC) (Im-PDVBVBC-NT) are synthesized by cationic polymerization and utilized as the gelators for ionic liquid based gel electrolytes. Compared with the synthesized pristine PDVBVBC-NT, Im-PDVBVBC-NT (a gelator dose as low as 1 wt%) based gel electrolytes show higher ionic conductivity and diffusion coefficient. The fabricated DSSCs based on Im-PDVBVBC-NT gel electrolyte show a power conversion efficiency of 4.9% and 5.5% under a simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2 and 50 mW cm−2, respectively. Furthermore, Im-PDVBVBC-NT based DSSCs show better long-term stability than that with ionic liquid electrolyte, which indicated that Im-PDVBVBC-NT based gel electrolytes could overcome the leakage problems of the cells with pure ionic liquid electrolytes.
Co-reporter:Wei Zhang, Lihua Qiu, Xiaojian Chen, Feng Yan
Electrochimica Acta 2014 Volume 117() pp:48-54
Publication Date(Web):20 January 2014
DOI:10.1016/j.electacta.2013.11.107
•We synthesize imidazolium functionalized bis-TEMPO redox couple.•We prepare PMII/Im-bisTEMPO based hybrid electrolyte.•The PMII/Im-bisTEMPO based hybrid electrolyte shows high redox potential.•The dye-sensitized solar cells achieve a power conversion efficiency of 8.8%.Imidazolium functionalized mono- and bis-TEMPO, 1-methyl-3-(4-(2,2,6,6-tetramethyl- 1-oxyl-4-piper-idoxyl)butyl)imidazolium bis(trifluoromethanesulfonyl) imide ([Im-TEMPO][TFSI]) and 1,3-bis(4-(2,2,6,6-tetramethyl-1-oxyl-4-piper-idoxyl)butyl)imidazolium bis(trifluoromethane- sulfonyl) imide ([Im-bisTEMPO][TFSI]), are synthesized and characterized. The prepared TEMPO based hybrid electrolyte shows negligible absorption in the visible region. Compared with the traditional I3−/I−, TEMPO/I−, Im-TEMPO/I− redox couples, [Im-bisTEMPO][TFSI]/I− hybrid redox couple displays the highest short circuit current density (Jsc), open circuit voltage (Voc) values, and exhibited an overall power conversion efficiency of 8.8% under simulated AM 1.5 solar spectrum irradiation at 100 mW cm-2. The enhanced photovoltaic performance might due to the lower electron recombination dynamics, negligible absorption in visible region of hybrid electrolytes and higher redox potential of the Im-bisTEMPO based redox couple.
Co-reporter:Chao Yuan, Jiangna Guo, Feng Yan
Polymer 2014 Volume 55(Issue 16) pp:3431-3435
Publication Date(Web):5 August 2014
DOI:10.1016/j.polymer.2014.03.024
Shape memory poly(ionic liquid) (PIL) gels with controllable macroscopic swelling degrees were prepared via host–guest interaction in this work. PILs with bis(trifluoromethyl-sulfonyl)imide (TFSI−) anions were synthesized by the radical copolymerization and immersed in water and β-cyclodextrins (β-CD) aqueous solutions, respectively. Quick swelling and shape memory behavior of the PIL gel were observed in β-CD aqueous solution due to the hydrophobic-to-hydrophilic transition induced by β-CD/TFSI− inclusion complexes. However, the PIL gel undergone only a slight swelling in the presence of water. The swelling of inclusion-sensitive polymer networks with shape memory effect prepared in this work would have applications in advanced sensor and biomedicine.
Co-reporter:Fenglou Gu, Huilong Dong, Youyong Li, Zhihong Si, and Feng Yan
Macromolecules 2014 Volume 47(Issue 1) pp:208-216
Publication Date(Web):December 19, 2013
DOI:10.1021/ma402334t
Imidazolium cations with various N3-substituents (including methyl, butyl, heptyl, dodecyl, isopropyl, and diphenylmethyl groups) were synthesized and investigated in terms of their alkaline stability. The effect of the N3-substituent on the alkaline stability was studied by quantitative 1H NMR spectra and density functional theory (GGA-BLYP) calculations. The isopropyl substituted imidazolium cation ([DMIIm]+) with the highest LUMO energy value exhibited the highest alkaline stability in aqueous NaOH. The [DMIIm]+ cation also exhibited higher alkaline stability than that of a quaternary ammonium cation, benzyltrimethyl-ammonium ([BTMA]+), in CD3OD/D2O NaOH solution at elevated temperatures. This observation inspired the preparation of [DMIIm]+-based alkaline anion exchange membranes (AEMs) which showed high alkaline stability in alkaline solution.
Co-reporter:Fenglou Gu, Huilong Dong, Youyong Li, Zhe Sun, and Feng Yan
Macromolecules 2014 Volume 47(Issue 19) pp:6740-6747
Publication Date(Web):September 30, 2014
DOI:10.1021/ma5015148
The synthesis and characterization of pyrrolidinium cation based anion exchange membranes (AEMs) are reported. Pyrrolidinium cations with various N-substituents (including methyl, ethyl, butyl, octyl, isopropyl, 2-hydroxylethyl, benzyl, and cyclohexylmethyl groups) were synthesized and investigated with respect to their chemical stability in alkaline media. The influence of substitutions on alkaline stability of pyrrolidinium cations was investigated by quantitative 1H nuclear magnetic resonance spectroscopy (NMR) and theoretical approaches. N,N-Ethylmethyl-substituted pyrrolidinium cation ([EMPy]+) exhibited the highest alkaline stability in this study. The synthesized AEMs based on [EMPy]+ show promising alkaline stability in strongly basic solution. The study of this work should provide a feasible way for improving the alkaline stability of pyrrolidinium cation based AEMs.
Co-reporter:Bencai Lin, Huilong Dong, Youyong Li, Zhihong Si, Fenglou Gu, and Feng Yan
Chemistry of Materials 2013 Volume 25(Issue 9) pp:1858
Publication Date(Web):March 27, 2013
DOI:10.1021/cm400468u
The alkaline stability of imidazolium salts and imidazolium-based alkaline anion-exchange membranes (AEMs) was investigated in this work. C2-substituted (with methyl, isopropyl or phenyl groups) imidazolium salts, 3-ethyl-1,2-dimethyl imidazolium bromine ([EDMIm][Br]), 3-ethyl-2-isopropyl-1-methylimidazolium bromine ([EIMIm][Br]), and 3-ethyl-1-methyl-2-phenyl- imidazolium bromine ([EMPhIm][Br]), were synthesized and characterized. The effect of the C2-substitution on the alkaline stability of imidazolium salts was investigated by 1H and 13C NMR spectroscopy. Compared with the C2-unsubstituted imidazolium salt, 3-ethyl-1-methylimidazolium bromine ([EMIm][Br]), the alkaline stability of C2-substituted imidazolium salts is significantly enhanced at elevated temperatures, probably due to the steric hindrance of the substituents, which protected the imidazolium cations against the hydroxide attack. Moreover, the higher LUMO energies may also improve the alkaline stability of imidazolium salts. The alkaline stability of C2-substituted imidazolium salts was found to be in the order [EDMIm][Br] > [EIMIm][Br] > [EMPhIm][Br]. This work provides a feasible approach for enhancing the chemical stability of C2-substituted imidazolium salts, which has potential applications for alkaline anion-exchange membranes.Keywords: alkaline stability; anion-exchange membranes; C2-substitution; energy level; imidazolium salts;
Co-reporter:Dan Xu, Haigang Zhang, Xiaojian Chen and Feng Yan
Journal of Materials Chemistry A 2013 vol. 1(Issue 38) pp:11933-11941
Publication Date(Web):05 Aug 2013
DOI:10.1039/C3TA12031G
CoII/III redox couples and their derivatives have been extensively studied and applied as redox mediators for high efficiency organic solvent DSSCs. However, CoII/III complex redox mediator-based ionic liquid electrolyte DSSCs have not been studied so far due to the poor solubility of most CoII/III complexes in ionic liquid electrolytes. Herein, an imidazolium functionalized cobalt tris(bipyridyl) complex redox mediator ([Co((MeIm-Bpy)PF6)3]2+/3+) (((MeIm-Bpy)PF6)3 = 3,3′-(2,2′-bipyridine-4,4′-diyl-bis(methylene))bis(1-methyl-1H-imidazol-3-ium)hexafluorohosphate) with high redox potential and good solubility in ionic liquid electrolyte has been synthesized and applied in ionic liquid electrolyte DSSCs. Using the dye N719 as the photosensitizer, overall power conversion efficiencies of 7.37% and 8.29% are achieved in binary ionic liquid-based electrolyte under 1.5 solar spectrum illumination at 100 and 50 mW cm−2, respectively. Both values are considerably higher than those of the I−/I3− redox couple-based ionic liquid electrolyte.
Co-reporter:Xiaojian Chen, Dan Xu, Lihua Qiu, Shichao Li, Wei Zhang and Feng Yan
Journal of Materials Chemistry A 2013 vol. 1(Issue 31) pp:8759-8765
Publication Date(Web):21 May 2013
DOI:10.1039/C3TA11521F
The imidazolium functionalized stable organic radical 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO), and 1-methyl-3-(2-oxo-2-(2,2,6,6-tetramethyl-1-oxyl-4-piperidoxyl) butyl)imidazolium bis(trifluoromethanesulfonyl) imide ([MeIm-TEMPO][TFSI]), were synthesized and characterized. The prepared [MeIm-TEMPO][TFSI]/1-propyl-3-methylimidazolium iodide (PMII) hybrid redox couple showed negligible absorption in the visible region and higher redox potential as compared with the iodide/triiodide (I−/I3−) redox couple. The resulting dye-sensitized solar cells (DSSCs) containing the imidazolium functionalized TEMPO/PMII hybrid redox couple in combination with organic dye (D205) exhibited average overall power conversion efficiencies of 8.2% and 9.1% under simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2 and 50 mW cm−2, respectively, which are higher than that of the traditional PMII/I2 based electrolyte, probably due to the enhancement of the Voc and Jsc values of the hybrid electrolytes.
Co-reporter:Chengzhen Shi, Shichao Li, Wei Zhang, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2013 vol. 1(Issue 44) pp:13956-13962
Publication Date(Web):2013/09/12
DOI:10.1039/C3TA12712E
A new family of organic ionic plastic crystals (OIPCs) based on bis-quaternary ammonium cations was synthesized and characterized. The synthesized bis-quaternary ammonium salts with bis(trifluoromethanesulfonyl) imide (TFSI−) anions exhibit plastic crystal properties as determined by differential scanning calorimetry (DSC). The high ionic conductivity of the compounds in the solid-state indicated that this new family of OIPCs can be promising solid-state electrolytes for electrochemical devices. Cyclic voltammetry characterization of OIPCs in the liquid-state revealed their wide electrochemical windows and highly reversible lithium metal electrodeposition properties.
Co-reporter:Yingjing Peng, Xiao Wu, Lihua Qiu, Changhai Liu, Suidong Wang and Feng Yan
Journal of Materials Chemistry A 2013 vol. 1(Issue 32) pp:9257-9263
Publication Date(Web):24 May 2013
DOI:10.1039/C3TA11676J
A facile and effective procedure for the synthesis of PtAu nanoparticles–carbon (PtAu–C) via the carbonization of triethoxysilane-derivatized ionic liquids is reported. A triethoxysilyl-functionalized ionic liquid, 1-methyl-3-[3-(triethoxysilyl)propyl]imidazolium chloride ([Si-pim][Cl]) was synthesized and anion-exchanged with a Pt precursor (H2PtCl6) and a Au precursor (HAuCl4) to form [Si-pim][PtCl6]x[AuCl4]y (the suffixes x and y represent the relative molar ratios of Pt and Au in the feed, respectively). The carbonization of [Si-pim][PtCl6]x[AuCl4]y, followed by hydrofluoric acid (HF) etching, produced PtxAuy–C hybrids. The composition of the PtxAuy alloy NPs can be controlled simply by adjusting the feed ratio in the metal precursor solution. The electrocatalytic properties of the prepared PtxAuy–C hybrids were determined by the composition of the alloy NPs. The resultant Pt–C hybrids show high electroactivity towards methanol oxidation in an acidic medium, while Pt4Au1–C shows high activity towards the reduction of 4-nitrophenol. The present study provides a highly efficient approach for the development of high-performance noble metals and their alloy-based catalysts.
Co-reporter:Bo Qiu, Congtao Pan, Wenjing Qian, Yingjing Peng, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2013 vol. 1(Issue 21) pp:6373-6378
Publication Date(Web):04 Apr 2013
DOI:10.1039/C3TA10774D
Nitrogen-doped mesoporous carbon materials are prepared via carbonization of a room temperature ionic liquid, 1-butyl-3-methylimidazolium dicyanamide (BMIMdca), using a mesoporous silica template (SBA-15). The nitrogen content and nanostructure of the resultant carbon materials are highly dependent on the carbonization temperature. The produced porous carbon materials were further applied as the electrode materials for supercapacitors. The porous structure and nitrogen functionalities enable carbon materials with a specific capacitance of 210 F g−1 at a current density of 1 A g−1 in a 6 M KOH aqueous solution. Furthermore, the nitrogen-doped porous carbon materials maintain a high capacitance retention capability (∼95%) after 1000 cycles at a current density of 1 A g−1, indicating that this kind of nitrogen-doped carbon material originated from room temperature ionic liquids is a promising electrode material for high-performance supercapacitors. These results may provide a facile synthesis of sulfur and nitrogen or multi-element doped porous carbon materials originated from ionic liquids for supercapacitors.
Co-reporter:Chengzhen Shi, Lihua Qiu, Xiaojian Chen, Haigang Zhang, Lei Wang, and Feng Yan
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 4) pp:1453
Publication Date(Web):February 5, 2013
DOI:10.1021/am302925s
Organic ionic plastic crystal, 1-propyl-1-methylpyrrolidinium iodide (P13I), which possesses a broad plastic phase from −36 to 135 °C, was doped with silica nanoparticles (SiO2 NPs) and 1-ethyl-3-methylimidazolium iodide (EMII), for the preparation of SiO2/EMII/P13I solid-state electrolytes for dye-sensitized solar cells (DSSCs). The thermal properties of all the electrolytes, including solid–solid phase transitions and melting temperatures, were investigated by differential scanning calorimetry (DSC). The effect of silica particles on the ionic conductivity, diffusion of I–/I3– redox couple in electrolytes, and photovoltaic performance for solid-state DSSCs were investigated. The fabricated solid-state DSSCs yielded a high power conversion efficiency of 5.25% under simulated air mass 1.5 solar spectrum illuminations at 50 mW cm–2. Furthermore, the DSSCs based on SiO2/EMII/P13I solid-state electrolytes show good stability after an accelerating aging test, demonstrating potential practical applications.Keywords: dye-sensitized solar cells; plastic ionic crystals; SiO2 nanoparticles; solid-state electrolyte; stability;
Co-reporter:Yingjing Peng, Changhai Liu, Congtao Pan, Lihua Qiu, Suidong Wang, and Feng Yan
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 7) pp:2752
Publication Date(Web):March 7, 2013
DOI:10.1021/am4004478
Polypyrrole nanotubes (PPyNTs)/PtAu alloy nanoparticle (NP) hybrids were synthesized in gram-scale by using covalently attached imidazolium moieties as a linker. The approach involves the surface functionalization of PPyNTs with pendant imidazolium moieties (PPyNT-Im), anion-exchange with Pt and Au precursors, and followed by the reduction of metal ions to produce the PtAu alloy NPs on the surface of PPyNTs. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and elemental mapping showed that both Pt and Au were atomically distributed in the PtAu alloy NPs without phase segregation. The composition of the PtAu alloy NPs can be simply controlled by adjusting the feed ratio in the metal precursor solution. The electrocatalytic properties of prepared PPyNT-Im-PtxAuy (the suffixes x and y represent the relative molar ratio of Pt and Au in the feed, respectively) NP hybrids were determined by the composition of alloy NPs. The Pt-rich NP hybrids, PPyNT-Im-Pt8Au2, showed highly electrocatalytic activity and stability toward the methanol oxidation in both acidic and alkaline solutions, whereas the Au-rich NP hybrids, PPyNT-Im-Pt2Au8, showed an enhanced catalytic activity and durability upon oxygen reduction. The present study provided a simple and effective approach for the preparation of PtAu alloy catalysts with controllable composition for high-performance fuel cells and electrochemical sensors.Keywords: electrocatalysts; methanol oxidation; oxygen reduction; polypyrrole nanotubes; PtAu alloy;
Co-reporter:Jiangna Guo, Yinxia Zhou, Lihua Qiu, Chao Yuan and Feng Yan
Polymer Chemistry 2013 vol. 4(Issue 14) pp:4004-4009
Publication Date(Web):09 May 2013
DOI:10.1039/C3PY00460K
Self-assembly behavior of amphiphilic random co-poly(ionic liquid)s in aqueous solution was investigated in this work. An imidazolium-type homopolymer, poly(1-(4-vinylbenzyl)-3-methyl imidazolium chloride) (denoted as PIL-[Cl]), was synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization of p-chloromethyl styrene, and followed by post-polymerization with methylimidazole (or vinylimidazole). Partial anion-exchange of PIL-[Cl] with PF6− anions yielded amphiphilic random copolymers, PIL-[Cl]x[PF6]y (suffixes x, y represent the relative molar ratio of Cl− and PF6− anions). Self-assembly morphologies of PIL-[Cl]x[PF6]y in aqueous solution as a function of copolymer composition (anions), molecular weight, and molecular weight distribution were investigated. The size of well-defined PIL-[Cl]x[PF6]y spherical micelles increased dramatically with increasing molecular weight distribution, while the anions and molecular weight show little effect on the micelle size. Furthermore, self-assembly of amphiphilic random ionic copolymers with the vinylimidazole groups yielded colloidosomes, which might be due to the polymerization of vinylimidazole groups.
Co-reporter:Jiangna Guo, Lihua Qiu, Zhijun Deng and Feng Yan
Polymer Chemistry 2013 vol. 4(Issue 5) pp:1309-1312
Publication Date(Web):18 Dec 2012
DOI:10.1039/C2PY21076B
Plastic 1–14 pH indicator strips were prepared via cross-linking of an ionic liquid (IL) monomer, 1-butyl-3-vinylimidazolium bromide ([Bvim][Br]), with acrylonitrile, and followed by anion-exchange with anionic dyes. The resultant pH indicator strips exhibit enhanced pH-responsive colour changes and robust pH-response reversibility in both aqueous and organic solutions.
Co-reporter:Dan Xu, Xiaojian Chen, Lei Wang, Lihua Qiu, Haigang Zhang, Feng Yan
Electrochimica Acta 2013 Volume 106() pp:181-186
Publication Date(Web):1 September 2013
DOI:10.1016/j.electacta.2013.05.091
•Pyridinyl-functionalized ionic liquid additive ([BuPyIm]Br) is synthesized.•[BuPyIm]Br shows low volatility and high thermal stability.•[BuPyIm]Br-based cell exhibits an efficiency of 6.69% and good long-term stability.•[BuPyIm]Br as additive avoids the negative features arising from volatile additives.A pyridinyl-functionalized ionic liquid, N-butyl-N′-(4-pyridylheptyl)imidazolium bromide ([BuPyIm]Br), is synthesized and applied as an additive for dye-sensitized solar cells (DSSCs). Compared with the volatile organic additive, 4-tert-butyl pyridine (TBP) (generally 0.5 M in the electrolyte), [BuPyIm]Br can be used at a very low concentration (0.1 M in the electrolyte) for high overall power conversion efficiency DSSCs, which shows an overall power conversion efficiency of 5.67% under the simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2 and 6.69% at 15 mW cm−2, respectively. Furthermore, [BuPyIm]Br-based DSSCs show better long-term stability than that of TBP-based devices. These results indicate that the DSSC devices based on the pyridinyl-functionalized ionic liquid additive can overcome the drawbacks of the volatile organic additive, and offer a feasible method to fabricate DSSCs in future practical applications.
Co-reporter:Bo Qiu;Bencai Lin
Polymer International 2013 Volume 62( Issue 3) pp:335-337
Publication Date(Web):
DOI:10.1002/pi.4454
Abstract
Ionic liquids are organic salts with melting points generally below 100 °C. They are attracting wide attention and are used as electrolytes in electrochemical devices, such as fuel cells, lithium-ion batteries, dye-sensitized solar cells, supercapacitors and light-emitting electrochemical cells, due to their negligible vapor pressure, high ionic conductivity and wide electrochemical window. This perspective article highlights the applications of ionic liquid- or poly(ionic liquid)-based electrolytes in fuel cells, dye-sensitized solar cells and supercapacitors. © 2013 Society of Chemical Industry
Co-reporter:Zhihong Si;Fenglou Gu;Jiangna Guo
Journal of Polymer Science Part B: Polymer Physics 2013 Volume 51( Issue 17) pp:1311-1317
Publication Date(Web):
DOI:10.1002/polb.23334
ABSTRACT
Phosphoric acid-doped crosslinked proton-conducting membranes with high anhydrous proton conductivity, and good chemical stability in phosphoric acid were synthesized and characterized. The synthetic procedure of the acid-doped composite membranes mainly involves the in situ crosslinking of polymerizable monomer oils (styrene and acrylonitrile) and vinylimidazole, and followed by the sulfonation of pendant imidazole groups with butanesultone, and further doped with phosphoric acid. The resultant phosphoric acid-doped composite electrolyte membranes are flexible and show high thermal stability and high-proton conductivity up to the order of 10−2 S cm−1 at 160 °C under anhydrous conditions. The phosphoric acid uptake, swelling degree, and proton conductivity of the composite membranes increase with the vinylimidazole content. The resultant composite membranes also show good oxidative stability in Fenton's reagent (at 70 °C), and quite good chemical stability in phosphoric acid (at 160 °C). The properties of the prepared electrolyte membranes indicate their promising prospects in anhydrous proton-exchange membrane applications. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013, 51, 1311–1317
Co-reporter:Zhijun Deng;Jiangna Guo;Lihua Qiu;Chao Yuan;Yinxia Zhou
Journal of Polymer Science Part A: Polymer Chemistry 2013 Volume 51( Issue 3) pp:664-671
Publication Date(Web):
DOI:10.1002/pola.26417
Abstract
Iron-mediated atom transfer radical polymerizations with activators generated by electron transfer of methyl methacrylate in N,N-dimethylformamide solution in the presence and absence of a limited amount of air, using FeCl3·6H2O as the catalyst, ethyl 2-bromoisobutyrate (EBiB) as the initiator, vitamin C as the reducing agent, and a commercially available organic acid, sulfosalicylic acid (SSA), as the ligand were investigated. Addition of SSA as the ligand could enhance the polymerization rate, and produce poly(methyl methacrylate) with controllable molecular weights and narrow molecular weight distributions (Mw/Mn = 1.30–1.50). The effect of [FeCl3·6H2O]0/[SSA]0 on the polymerization was studied by cyclic voltammetry characterization. Chain extension was performed to confirm the “living”/controlled nature of the polymerization system. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Co-reporter:Qing Li;Jie Zhao;Baoquan Sun;Bencai Lin;Lihua Qiu;Yueguang Zhang;Xiaojian Chen;Jianmei Lu
Advanced Materials 2012 Volume 24( Issue 7) pp:945-950
Publication Date(Web):
DOI:10.1002/adma.201103976
Co-reporter:Fuqiang Chu, Bencai Lin, Bo Qiu, Zhihong Si, Lihua Qiu, Zongzong Gu, Jianning Ding, Feng Yan and Jianmei Lu
Journal of Materials Chemistry A 2012 vol. 22(Issue 35) pp:18411-18417
Publication Date(Web):27 Jul 2012
DOI:10.1039/C2JM32787B
Polybenzimidazole (PBI)/H3PO4/zwitterion-coated silica nanoparticle hybrid proton conducting membranes for anhydrous proton-exchange membrane application were synthesized and characterized. Fluorine-containing PBI was synthesized via the condensation polymerization of 3,3-diaminobenzidine and 2-bis(4-carboxyphenyl) hexafluoropropane in poly(phosphoric acid) at 170 °C. Zwitterion-coated silica nanoparticles were synthesized via the hydrolysis and polycondensation of zwitterionic organosiloxane, and applied as the additive for the PBI-based hybrid proton conducting membranes. The synthesized phosphoric acid doped polymeric composite membranes were transparent, flexible and showed high proton conductivities of up to 1 × 10−2 S cm−1 at 160 °C under anhydrous conditions. Addition of zwitterion-coated silica nanoparticles to the PBI membrane dramatically increased the phosphoric acid doping capacity, and slightly improved the chemical stability of the composite membranes. Compared with pure PBI membranes, zwitterion-coated SiO2 nanoparticles are effective in preventing the release of the phosphoric acid component from the composite membranes. These properties enable this type of hybrid membrane to be suitable for high-temperature polymer electrolyte membrane fuel cells.
Co-reporter:Jie Zhao, Baoquan Sun, Lihua Qiu, Huizi Caocen, Qing Li, Xiaojian Chen and Feng Yan
Journal of Materials Chemistry A 2012 vol. 22(Issue 35) pp:18380-18386
Publication Date(Web):24 Jul 2012
DOI:10.1039/C2JM32607H
Light-scattering functionalized cyanobiphenyl-based benzimidazole was synthesized and applied in the surface modification of dyed TiO2 photoanodes for dye-sensitized solar cells (DSSCs). DSSCs based on the ionic liquid and all-solid-state electrolytes were fabricated and characterized, without the addition of additives in the electrolytes. Compared with electrolytes containing the additive N-butylbenzimidazole (NBB), surface modification of dyed TiO2 photoanodes with cyanobiphenyl-based benzimidazole could enhance the values of the open-circuit photovoltage (Voc), short-circuit photocurrent density (Jsc) and the overall PCE of the fabricated DSSCs, due to the suppressed charge recombination rate, the conductivity optimization of the electrolytes and enhanced light harvesting capability at the TiO2 photoanode/electrolyte interface. Under the simulated air mass 1.5 solar spectrum illuminations at 100 mW cm−2, the fabricated devices achieved a cell efficiency of ∼6.63% and ∼5.82% for ionic liquid and all-solid-state electrolytes, respectively. These results provide an alternative strategy for high performance DSSCs with additive-free electrolytes.
Co-reporter:Xiaojian Chen, Jie Zhao, Jinyu Zhang, Lihua Qiu, Dan Xu, Haigang Zhang, Xiaoyuan Han, Baoquan Sun, Gaohui Fu, Ye Zhang and Feng Yan
Journal of Materials Chemistry A 2012 vol. 22(Issue 34) pp:18018-18024
Publication Date(Web):13 Jul 2012
DOI:10.1039/C2JM33273F
Bis-imidazolium based poly(ionic liquid), poly(1-butyl-3-(1-vinylimidazolium-3-hexyl)-imidazolium bis(trifluoromethanesulfonyl)imide) (Poly[BVIm][HIm][TFSI]) and mono-imidazolium based poly(ionic liquid), poly(1-butyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide) (Poly[BVIm][TFSI]), were synthesized and dissolved in room temperature ionic liquids (ILs) to form quasi-solid-state electrolytes for dye-sensitized solar cells (DSSCs), without using any volatile organic solvent. Compared with mono-imidazolium based poly[BVIm][TFSI], bis-imidazolium based poly[BVIm][HIm][TFSI] electrolytes showed a higher thermal stability and conductivity due to the charge transport networks formed in the gel electrolytes via the π–π stacked imidazolium rings. The DSSCs based on the poly[BVIm][HIm][TFSI] gel electrolyte showed a superior long-term stability and yielded a power conversion efficiency of 5.92% under the simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2. This study offered a feasible method to fabricate quasi-solid-state DSSCs in future practical applications.
Co-reporter:Congtao Pan, Lihua Qiu, Yingjing Peng and Feng Yan
Journal of Materials Chemistry A 2012 vol. 22(Issue 27) pp:13578-13584
Publication Date(Web):16 May 2012
DOI:10.1039/C2JM31973J
A polymerizable ionic liquid (IL), 1-butyl-3-vinylimidazolium bromide ([Bvim][Br]), was synthesized and copolymerized with acrylonitrile to produce poly(1-butyl-3-vinylimidazolium bromide-co-acrylonitrile) (PBA). Carbonization of PBA yielded carbon materials. The carbon yield, nitrogen content and nanostructure of carbon materials are highly dependent on the IL molar ratio in the co-polymers. The synthesized PBA was anion-exchanged with Pt precursor (H2PtCl6) to form [PBA][PtCl6]. Carbonization of [PBA][PtCl6] produced nitrogen-doped carbon–Pt nanohybrids, which showed a high catalytic activity and stability for electrocatalytic oxidation of methanol. The present study provided a novel method for the development of high performance electrocatalysts based on nitrogen-doped carbon–Pt or other noble metals and their alloys for fuel cells or electrochemical sensors.
Co-reporter:Huizi Cao-Cen, Jie Zhao, Lihua Qiu, Dan Xu, Qing Li, Xiaojian Chen and Feng Yan
Journal of Materials Chemistry A 2012 vol. 22(Issue 25) pp:12842-12850
Publication Date(Web):02 May 2012
DOI:10.1039/C2JM31551C
Organic ionic crystals carrying 4-cyano-4′-hydroxybiphenyl and imidazolium units were synthesized and applied as the electrolytes for dye-sensitized solar cells (DSSCs). The fabricated all-solid-state DSSCs achieved a cell efficiency of ∼5.11% at 55 °C under the simulated air mass 1.5 solar spectrum illuminations at 100 mW cm−2 because of the enhanced light harvesting capability of the electrolyte. To further improve the cell efficiency, 1-propyl-3-methylimidazolium iodine (PMII), was added into the electrolytes as a crystal growth inhibitor. These fabricated devices showed an enhanced power conversion efficiency (PCE) of ∼6.55% at 45 °C under the simulated air mass 1.5 solar spectrum illuminations at 50 mW cm−2, and a superior long-term stability. The cyanobiphenyl-functionalized ionic crystal based electrolytes have expanded our vision to explore new types of all-solid-state electrolytes for high-efficiency DSSCs.
Co-reporter:Qing Li, Xiaojian Chen, Jie Zhao, Lihua Qiu, Yueguang Zhang, Baoquan Sun and Feng Yan
Journal of Materials Chemistry A 2012 vol. 22(Issue 14) pp:6674-6679
Publication Date(Web):24 Feb 2012
DOI:10.1039/C2JM16850B
An organic ionic plastic crystal, 1-ethyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (P12TFSI), was synthesized and doped with a room temperature ionic liquid, 1-propyl-3-methylimidazolium iodide (PMII). The prepared PMII/P12TFSI solid-state electrolytes were employed for dye-sensitized solar cells (DSSCs), without using any volatile organic solvent. The fabricated solid-state DSSCs yielded a power conversion efficiency of 5.12% under simulated air mass 1.5 solar spectrum illuminations at 50 mW cm−2. The superior long-term stability of the fabricated solid-state DSSCs indicated that the synthesized PMII/P12TFSI solid-state electrolytes could overcome the drawbacks of cells containing volatile solvents.
Co-reporter:Bo Qiu, Bencai Lin, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2012 vol. 22(Issue 3) pp:1040-1045
Publication Date(Web):14 Nov 2011
DOI:10.1039/C1JM14331J
Alkaline imidazolium-type ionic liquids (ILs) and quaternary ammonium salt functionalized alkaline anion-exchange membranes (AEMs), with the same ion exchange capacity (IEC), were synthesized via in situ cross-linking of styrene, acrylonitrile, 1-methyl-3-(4-vinylbenzyl)imidazolium chloride ([MVBIm][Cl]), and N,N,N-trimethyl-1-(4-vinylphenyl) methanaminium chloride ([TMVPMA][Cl]), respectively. The water uptake, swelling ratio, conductivity, and alkaline stability of resultant cross-linked copolymer membranes were investigated. Both types of copolymer membranes exhibit hydroxide conductivity above 10−2 S cm−1 at room temperature. Alkaline imidazolium-type IL functionalized membranes showed an excellent chemical stability of up to 1000 h without obvious loss of ion conductivity, whereas the membranes based on quaternary ammonium salts degraded in high pH solution because of nucleophillic substitution on quaternary ammonium cations. The results of this study suggest that the AEMs based on alkaline imidazolium-type ILs are expected to promote the widespread use of alkaline fuel cells.
Co-reporter:Zhijun Deng, Jiangna Guo, Lihua Qiu, Yinxia Zhou, Lin Xia and Feng Yan
Polymer Chemistry 2012 vol. 3(Issue 9) pp:2436-2443
Publication Date(Web):21 May 2012
DOI:10.1039/C2PY20262J
Imidazolium-type basic ionic liquids (BILs), including 1-butyl-3-methyl imidazolium hydroxide ([Bmim][OH]), 1-butyl-3-methyl imidazolium phosphate ([Bmim][PO4]), 1-butyl-3-methyl imidazolium carbonate ([Bmim][CO3]), and 1-butyl-3-methyl imidazolium bicarbonate ([Bmim][HCO3]), coordinated by iron chloride (FeCl3·6H2O), were used as both the ligand and catalyst in activators generated by the electron transfer ATRP (AGET ATRP) of methyl methacrylate (MMA) in bulk and solution, without the use of traditional ligands (such as 2,2-bipyridine, tetrabutylammonium bromide, and tetra-n-butylphosphonium bromide). Catalytic amounts of BILs could enhance the initiator efficiency (0.87–0.91) and the polymerization rate, and produce PMMA with controllable molecular weights and narrow molecular weight distributions (Mw/Mn = 1.20–1.40). The nature of the controlled/“living” free radical polymerization in the presence of BILs was confirmed by chain-extension experiments. The ready solubility and availability of BILs enable them to be applied as a new type of ligand and catalyst in iron-mediated AGET ATRP.
Co-reporter:Bo Qiu, Bencai Lin, Zhihong Si, Lihua Qiu, Fuqiang Chu, Jie Zhao, Feng Yan
Journal of Power Sources 2012 Volume 217() pp:329-335
Publication Date(Web):1 November 2012
DOI:10.1016/j.jpowsour.2012.06.041
Novel anion-exchange membranes (AEMs) are prepared via in situ cross-linking of styrene, acrylonitrile and the bis-imidazolium functionalized ionic liquid monomer, 1-allyl-3-(6-(1-butyl-2-methylimidazol-3-ium-3-yl)hexyl)-2-methylimidazol-3-ium bromide ([ABMHM][Br]2), and followed by anion-exchange with hydroxide ions. The morphology and characteristic properties of the resultant copolymer membranes, such as the water uptake, swelling ratio, ion exchange capacity (IEC), hydroxide conductivity, and chemical stability are investigated. The membrane containing 40% mass fraction of [ABMHM][OH]2 shows hydroxide conductivity up to 2.0×10−2 S cm−1 and good long-term stability in 1 M KOH solution at 60 °C. The results of this study suggest that the AEMs based on bis-imidazolium cations have good perspectives for alkaline fuel cell applications.Graphical abstractAlkaline bis-imidazolium-based anion-exchange membranes show good alkaline stability up to 30 days in 1 M KOH at 60 °C.Highlights► We synthesize bis-imidazolium functionalized ionic liquid monomers. ► We prepare bis-imidazolium-based anion-exchange membranes. ► The membranes show a hydroxide conductivity up to 2.0×10−2 S cm−1 at 60 °C. ► The membranes show an excellent chemical stability.
Co-reporter:Xiaojian Chen, Qing Li, Jie Zhao, Lihua Qiu, Yueguang Zhang, Baoquan Sun, Feng Yan
Journal of Power Sources 2012 Volume 207() pp:216-221
Publication Date(Web):1 June 2012
DOI:10.1016/j.jpowsour.2012.01.143
Ionic liquid-tethered TiO2 nanoparticles are prepared by tethering 1-methyl-3-[(triethoxysilyl)propyl]imidazolium chloride (TMICl) to TiO2 nanoparticles. The quasi-solid-state dye-sensitized solar cells containing 15 wt% of ionic liquid-tethered nanoparticle/poly(ionic liquid) hybrid electrolytes show an overall power conversion efficiency of ∼5.67% under simulated AM 1.5 solar spectrum irradiation at 50 mW cm−2. Compared with unmodified TiO2 nanoparticles, ionic liquid-tethered nanoparticle based hybrid gel electrolytes show enhanced short circuit current density (Jsc), open circuit voltage (Voc), photoelectric conversion efficiency (η), and better long-term stability of the devices. These results indicate that the cells based on ionic liquid-tethered nanoparticle hybrid electrolytes could overcome the drawbacks of volatile liquid electrolytes, and offer a feasible method to fabricate quasi-solid-state DSSCs in future practical applications.Graphical abstractThe quasi-solid-state dye-sensitized solar cells based on ionic liquid tethered TiO2/poly(ionic liquid) were fabricated and characterized.Highlights► We synthesize ionic liquid (IL) tethered TiO2 nanoparticles. ► We fabricate IL-TiO2/poly(ionic liquid) quasi-solid-state electrolytes. ► The quasi-solid-state dye-sensitized solar cells show a power conversion efficiency of 5.26%. ► The quasi-solid-state dye-sensitized solar cells show excellent long-term stability.
Co-reporter:Yingjing Peng, Lihua Qiu, Congtao Pan, Cancan Wang, Songmin Shang, Feng Yan
Electrochimica Acta 2012 Volume 75() pp:399-405
Publication Date(Web):30 July 2012
DOI:10.1016/j.electacta.2012.05.034
Water dispersible polypyrrole nanotube/silver nanoparticle hybrids (PPyNT-COOAgNP) were synthesized via a cation-exchange method. The approach involves the surface functionalization of PPyNTs with carboxylic acid groups (COOH), and cation-exchange with silver ions (Ag+) and followed by the reduction of metal ions. The morphology and optical properties of the produced PPyNT-COOAgNP nanohybrids were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectrometer, and UV–vis spectroscopy. The as-prepared PPyNT-COOAgNP nanohybrids exhibited well-defined response to the reduction of hydrogen peroxide, and as extremely suitable substrates for surface-enhanced Raman spectroscopy (SERS) with a high enhancement factor of 6.0 × 107, and enabling the detection of 10−12 M Rhodamine 6G solution.
Co-reporter:Yueguang Zhang, Jie Zhao, Baoquan Sun, Xiaojian Chen, Qing Li, Lihua Qiu, Feng Yan
Electrochimica Acta 2012 Volume 61() pp:185-190
Publication Date(Web):1 February 2012
DOI:10.1016/j.electacta.2011.12.003
Quasi-solid-state ionic liquid (IL) gel electrolytes for dye-sensitized solar cells (DSSCs) are prepared via dispersion of multi-wall carbon nanotubes (MWCNTs) in room temperature ILs. Addition of MWCNTs significantly increases the viscosity as well as the conductivity of MWCNT-based IL gels. Compared with raw MWCNTs, acid-oxidized MWCNTs improve the miscibility with ILs, which results in an enhanced gel-forming ability of MWCNT/IL gels. The solar cells based on acid-oxidized MWCNT/IL gel electrolytes yield the power conversion efficiency of 5.74% under the simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2. The superior long-term stability of fabricated DSSCs indicates that the cells based on acid-oxidized MWCNT/IL gel electrolyte could overcome the drawbacks of volatile liquid electrolytes.
Co-reporter:Zhijun Deng;Lihua Qiu;Liangjiu Bai;Yinxia Zhou;Bencai Lin;Jie Zhao;Zhenping Cheng;Xiulin Zhu
Journal of Polymer Science Part A: Polymer Chemistry 2012 Volume 50( Issue 8) pp:1605-1610
Publication Date(Web):
DOI:10.1002/pola.25931
Abstract
A basic ionic liquid, 1-butyl-3-methyl imidazolium hydroxide ([Bmim]OH), was synthesized and used as the additives in an iron-mediated atom transfer radical polymerization with activators generated by electron transfer (AGET ATRP) of methyl methacrylate in bulk and solution, using FeCl3·6H2O as the catalyst, ethyl 2-bromoisobutyrate as the initiator, vitamin C (Vc) as the reducing agent, and tetrabutylammonium bromide or tetra-n-butylphosphonium bromide as the ligand. Catalytic amount of [Bmim]OH could enhance the polymerization rate and produce poly(methyl methacrylate) with controllable molecular weights and narrow molecular weight distributions (Mw/Mn = 1.3–1.4). The nature of controlled/“living” free radical polymerization in the presence of basic ionic liquid was further confirmed by chain-extension experiments. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Co-reporter:Jie Zhao, Xiaojuan Shen, Feng Yan, Lihua Qiu, Shuittong Lee and Baoquan Sun
Journal of Materials Chemistry A 2011 vol. 21(Issue 20) pp:7326-7330
Publication Date(Web):04 Apr 2011
DOI:10.1039/C1JM10346F
Photochemically stable poly(ionic liquids) (poly(ILs)) including poly(1-butyl-3-vinylimidazolium bromide) ([PBVIm][Br]) and poly(1-butyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide) ([PBVIm][TFSI]) were synthesized and dissolved in the room temperature ionic liquids (ILs) to form quasi-solid-state electrolytes for dye-sensitized solar cells (DSSCs), without using any volatile organic solvent. DSSCs based on IL/[PBVIm][TFSI] gel electrolyte yielded a power conversion efficiency of 4.4% under a simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2. The superior long-term stability of fabricated DSSCs indicated that the DSSCs based on solvent-free IL/poly(ILs) gel electrolytes could overcome the drawbacks of cells containing volatile solvents.
Co-reporter:Jie Zhao, Feng Yan, Lihua Qiu, Yueguang Zhang, Xiaojian Chen and Baoquan Sun
Chemical Communications 2011 vol. 47(Issue 41) pp:11516-11518
Publication Date(Web):23 Sep 2011
DOI:10.1039/C1CC15069C
Benzimidazolyl functionalized ionic liquids were synthesized and applied as additives for dye-sensitized solar cells. The fabricated devices show an overall power conversion efficiency of ∼7.79% under AM 1.5 radiation (50 mW cm−2), and an excellent long-term stability.
Co-reporter:Lihua Qiu, Baoqiang Liu, Yingjing Peng and Feng Yan
Chemical Communications 2011 vol. 47(Issue 10) pp:2934-2936
Publication Date(Web):24 Jan 2011
DOI:10.1039/C0CC04865H
Polypyrrole
nanotubes (PPyNTs)/Pt nanoparticle hybrids were synthesized by using covalently attached imidazolium-type ionic liquids (ILs) as linkers. The resultant Pt/ILs/PPyNTs hybrids exhibited high electrocatalytic activity in electrocatalytic oxidation of methanol.
Co-reporter:Fuqiang Chu, Bencai Lin, Feng Yan, Lihua Qiu, Jianmei Lu
Journal of Power Sources 2011 Volume 196(Issue 19) pp:7979-7984
Publication Date(Web):1 October 2011
DOI:10.1016/j.jpowsour.2011.05.064
A type of anhydrous proton-conducting membranes are prepared via in situ cross-linking of polymerizable oils containing polyamidoamine (PAMAM) dendrimer-based macromolecular protic ionic liquids (PILs). The resultant composite membranes are transparent, flexible, and thermally stable up to 350 °C. Under anhydrous conditions, the macromolecular PIL-based membranes show proton conductivity of 1.2 × 10−2 S cm−1 at 160 °C, which is higher than that of the membranes containing small-molecule PILs. Furthermore, the macromolecular PIL-based composite membranes have much better PIL retention ability than which containing small-molecule PILs. These properties make this type of macromolecular PIL-based membranes suitable for high-temperature anhydrous polymer electrolyte membrane fuel cells.Highlights► We synthesize anhydrous proton-conducting composite membranes based on macromolecular protic ionic liquids (PILs). ► We characterize the resultant composite membranes. ► The composite membranes show proton conductivity up to 1.2 × 10−2 S cm−1 at 160 °C. ► The composite membranes show good PIL retention ability.
Co-reporter:Jianhu Yang;Lihua Qiu;Baoqiang Liu;Yingjing Peng;Songmin Shang
Journal of Polymer Science Part A: Polymer Chemistry 2011 Volume 49( Issue 21) pp:4531-4538
Publication Date(Web):
DOI:10.1002/pola.24895
Abstract
Herein, we present a facile approach for the synthesis of polymeric ionic liquids (PILs) microspheres for metal scavenging and catalysis. Crosslinked poly(1-butyl-3-vinylimidazolium bromide) microspheres with the diameter of about 200 nm were synthesized via miniemulsion polymerization, in which 1,4-di(vinylimidazolium) butane bisbromide was added as the crosslinker. Anion exchange of PIL microspheres with Pt precursor and followed by the reduction of Pt ions produced PIL microsphere supported Pt nanoparticle hybrids. The synthesized Pt nanoparticles with a diameter of about 2 nm are uniformly dispersed and strongly bound to the surface of PIL microspheres. The catalytic performances of PIL/Pt nanoparticle hybrids were evaluated for both the electrocatalytic oxidation of methanol and oxidation of benzyl alcohol. The PIL/Pt nanoparticle hybrids show better electrocatalytic activity towards the electrooxidation of methanol than pure Pt nanoparticles. Furthermore, they are effective and easily reusable catalysts for the selective oxidation of benzyl alcohol in aqueous reaction media, demonstrating that the synthesized PIL microspheres are suitable scaffolds for heterogeneous catalysts Pt. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Co-reporter:Xia Sun ; Dong-Ying Zhou ; Lihua Qiu ; Liang-Sheng Liao
The Journal of Physical Chemistry C 2011 Volume 115(Issue 5) pp:2433-2438
Publication Date(Web):January 6, 2011
DOI:10.1021/jp1099656
Improvement of electron injection is one of the most effective ways for obtaining highly efficient low-voltage organic light-emitting diodes (OLEDs). Here, we report the study on the unidentate sodium−quinolate complexes as the electron injection layer for OLEDs. Sodium−quinolate complexes, 8-hydroxyquinolinolatosodium (Naq), 2-methyl-8-hydroxyquinolinolatosodium (NaMeq), and 2-(diphenylmethyl)-8-hydroxyquinolatosodium (Ph2Naq) were synthesized and characterized by 1H NMR, 13C NMR, FTIR, UV−vis, and photoluminescence (PL) spectroscopy. The produced sodium−quinolate complexes are thermally stable amorphous compounds with high glass transition and decomposition temperatures. These complexes were used as the electron injection materials for multilayer OLEDs. In the case of OLEDs using 2-methyl-9,10-bis(naphthalene-2-yl)anthracene (MADN) as the electron transport layer (ETL), Naq and NaMeq show much better performance than LiF in OLED devices.
Co-reporter:Yinxia Zhou, Lihua Qiu, Zhijun Deng, John Texter, and Feng Yan
Macromolecules 2011 Volume 44(Issue 20) pp:7948-7955
Publication Date(Web):September 16, 2011
DOI:10.1021/ma201545x
Sustainable atom transfer radical polymerization of methyl methacrylate (MMA) with activators generated by electron transfer (AGET ATRP) was done using microemulsion polymerization at the relatively low temperature of 30 °C. Ethyl 2-bromoisobutyrate (EBiB) was used as ATRP initiator, ascorbic acid (AA) was used as reducing agent, and CuCl2/N-bis(2-pyridylmethyl)octylamine (BPMOA) was used as catalyst. Microemulsion AGET ATRP of MMA was well-controlled, producing poly(methyl methacrylate) (PMMA) nanoparticles ∼5 nm in diameter and narrow molecular weight distributions (Mw/Mn = 1.20–1.40). After the polymerization and isolation of PMMA, the mixture containing catalysts and ILs was shown to be recoverable and recyclable. Upon replenishment of initiator, reducing agent, and monomer (MMA), AGET ATRP of MMA produced PMMA with reproducible molecular weights and narrow molecular weight distributions, even in the fifth cycle. Thus, this process was demonstrated as being sustainable. Furthermore, use of a new surfactant IL ligand, 3-{11-[(3-(bis(pyridin-2-ylmethyl)amino)propanoyl)oxy]undecyl}-1-methylimidazolium bromide (BPYP-[MIM]Br) or 3-{11-[(3-(bis(pyridin-2-ylmethyl)amino)propanoyl)-oxy]undecyl}-1-methylimidazolium hexafluorophosphorate (BPYP-[MIM]PF6), demonstrated rate-enhanced polymerization relative to the use of BPMOA as ligand, and good polydispersity (Mw/Mn = 1.20–1.50) of the resultant PMMA was maintained.
Co-reporter:Bencai Lin, Lihua Qiu, Bo Qiu, Yu Peng, and Feng Yan
Macromolecules 2011 Volume 44(Issue 24) pp:9642-9649
Publication Date(Web):November 30, 2011
DOI:10.1021/ma202159d
Solvent processable polyfluorene ionomers with pendant imidazolium groups were synthesized and characterized. The synthesized polymeric membranes are transparent, flexible, and mechanically strong and exhibit hydroxide ion conductivity above 10–2 S/cm at room temperature. The membranes are soluble in polar aprotic solvents such as DMSO and DMF, while insoluble in water and aqueous methanol. The solubility properties of polyfluorene ionomers enable the use for not only alkaline anion-exchange membrane but also ionomer electrode material. 1H NMR and hydroxide ion conductivity measurements demonstrated an excellent chemical stability of the synthesized polyfluorene ionomers in high-pH solution at elevated temperatures. The results of the study suggest a feasible approach for the synthesis and practical applications of alkaline anion-exchange membranes (AEMs).
Co-reporter:Bencai Lin, Lihua Qiu, Jianmei Lu, and Feng Yan
Chemistry of Materials 2010 Volume 22(Issue 24) pp:6718
Publication Date(Web):December 3, 2010
DOI:10.1021/cm102957g
We report an effective and simplified procedure for the synthesis of cross-linked alkaline anion-exchange membranes (AEMs). AEMs based on alkaline imidazolium-type ionic liquids (ILs) were prepared via in situ cross-linking of 1-vinyl-3-methylimidazolium iodide ([VMIm][I]) with styrene and acrylonitrile, and followed by anion-exchange with hydroxide ions. The resulting cross-linked copolymer membranes exhibit high hydroxide ion conductivity (above 10−2 S/cm at room temperature) and good mechanical properties. The thermal stability of the produced AEMs is comparable to that of quaternary ammonia aromatic polymers. The membranes display an excellent chemical stability up to 400 h in high pH solution without an obvious loss of ion conductivity and mechanical properties. This synthetic procedure avoids the use of chloromethyl methyl ether and solution casting generally used for AEMs preparation. The results of the study suggest a feasible approach for the synthesis and practical applications of alkaline AEMs and are expected to promote the widespread use of alkaline fuel cells.
Co-reporter:Bencai Lin, Si Cheng, Lihua Qiu, Feng Yan, Songmin Shang and Jianmei Lu
Chemistry of Materials 2010 Volume 22(Issue 5) pp:1807
Publication Date(Web):January 11, 2010
DOI:10.1021/cm9033758
A new type of proton-conducting hybrid membranes were prepared by in situ cross-linking of a mixture of polymerizable oils containing protic ionic liquids (PILs) and silica nanoparticles or mesoporous silica nanospheres. The resultant hybrid membranes are semitransparent, flexible, and show good thermal stability, good and tunable mechanical properties. Incorporation of proper amount of silica fillers significantly increased the proton conductivity of the membranes, probably due to the ion transport channel or network structures formed in the membranes. However, further addition of silica fillers might block the formed ion transport channels and decrease the conductivity of hybrid membranes. Compared with silica nanoparticles, mesoporous silica nanospheres is more effective in enhancing the conductivity and in preventing the release of ionic liquid component from the composite membranes. Under anhydrous conditions, the produced hybrid membranes show proton conductivity up to the order of 1 × 10−2 S/cm at 160 °C. These properties make this type of PIL-based hybrid membranes suitable for high-temperature polymer electrolyte membrane fuel cells.
Co-reporter:Zhenzhen Chen, Feng Yan, Lihua Qiu, Jianmei Lu, Yinxia Zhou, Jiaxin Chen, Yishan Tang and John Texter
Langmuir 2010 Volume 26(Issue 6) pp:3803-3806
Publication Date(Web):February 19, 2010
DOI:10.1021/la100502x
Free radical and atom-transfer radical polymerizations were conducted in monomer/ionic liquid microemulsions. After the polymerization and isolation of the resultant polymers, the mixture of the catalyst and ionic liquids (surfactant and continuous phase) can be recovered and reused, thereby dramatically improving the environmental sustainability of such chemical processing. The addition of monomer to recovered ionic liquid mixtures regenerates transparent, stable microemulsions that are ready for the next polymerization cycle upon addition of initiator. The method combines the advantages of IL recycling and microemulsion polymerization and minimizes environmental disposable effects from surfactants and heavy metal ions.
Co-reporter:Jingya Shi, Peiyi Wu and Feng Yan
Langmuir 2010 Volume 26(Issue 13) pp:11427-11434
Publication Date(Web):June 10, 2010
DOI:10.1021/la1009225
The intermolecular interaction and distribution of components in [Bmim][BF4]-based polystyrene composite membrane which is composed of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]), poly(1-(2-methyl acryloyloxyundecyl)-3-methylimidazolium bromide) (poly(MAUM-Br)) and polystyrene is investigated by in situ Fourier transform infrared spectroscopy (FTIR) and two-dimensional correlation infrared spectroscopy (2DIR) in this study. A proposed model about the structure of this composite material is presented, and a sketch map about the local distributions of components is provided. In this model, alkyl chains in [Bmim][BF4], poly(MAUM-Br), and polystyrene in this system were supposed to form a polymeric network through aggregation or copolymerization. Cations of ionic liquids separate into the polymer network, while anions are kept mainly through the Coulomb force and partially by the hydrogen bonding between cations and anions. To support this model, FTIR has provided some hints on the π−π interaction existing in this complex material between the imidazole ring of ionic liquids and the benzene ring of polystyrene, based on the discovery of the shifts of IR absorption bands assigned to the C−C stretching vibrational mode. The sequential order of the responses from different chemical groups toward the variation of temperature is calculated by 2DIR, and the results suggest how different components distributed in this [Bmim][BF4]-based polystyrene composite membrane.
Co-reporter:Hanbin Diao, Feng Yan, Lihua Qiu, Jianmei Lu, Xinhua Lu, Bencai Lin, Qing Li, Songmin Shang, Wenming Liu and Jianguo Liu
Macromolecules 2010 Volume 43(Issue 15) pp:6398-6405
Publication Date(Web):July 14, 2010
DOI:10.1021/ma1010099
Poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) has been used for the preparation of proton exchange membranes (PEMs) due to the superior ability of sulfonic acid groups originated from AMPS in supporting proton conduction. Since PAMPS is water-swollen or even soluble in water, it is necessary to copolymerize AMPS with proper monomer oils to control the swelling and mechanical properties of membranes. However, as a water-soluble monomer, AMPS is generally immiscible with hydrophobic monomer oils. To overcome this obstacle, AMPS was converted to an ionic liquid (IL) form by neutralization with a Brønsted base, 1-methylimidazole. The resultant 1-methylimidazolium 2-acrylamido-2-methylpropanesulfonate ([MIm][AMPS]) is miscible with monomer oils and thus could be cross-linked with styrene, acrylonitrile, and divinylbenzene. The produced copolymer membranes in IL form were converted to acid form by treated with acid. Membranes in both IL and acid forms have good thermal stability and mechanical properties which could be further tuned by the content of cross-linking agent. The water uptake, swelling degree, proton conductivity, and methanol permeability of the membranes increased with the PAMPS content while decreased with cross-link agent content. The acid form PAMPS-based membranes showed high proton conductivity of 3.82 × 10−2 S/cm and low methanol permeability of 3.80 × 10−7 cm2/s at 25 °C. The properties of the samples suggested that this type of cross-linked PAMPS-based membranes were particularly promising to be used as PEMs in direct methanol fuel cells.
Co-reporter:Jianmei Lu, Feng Yan, John Texter
Progress in Polymer Science 2009 Volume 34(Issue 5) pp:431-448
Publication Date(Web):May 2009
DOI:10.1016/j.progpolymsci.2008.12.001
Ionic liquids (ILs) are continuing as important media in which to effect various kinds of polymerizations, and it is particularly noteworthy that ionic polymerizations are being developed in IL solvents and that atom transfer radical polymerization (ATRP) catalysts are being attached to ILs to make them more easily recoverable in living polymerizations. In addition, the number of polymerizable ILs is steadily increasing, and ionic liquid polymers of polymerizable ionic liquid monomers have been produced as exotic polyelectrolytes. ILs are being used as plasticizers of various kinds of polymers and as key components in new classes of polymer gels. Polymers and inorganic substrates are being used to support ILs through covalent binding of the ILs, in which case the properties of the IL are modified to some extent, and polymer membranes and porous materials absorb ILs with concomitant changes in ionic conductivity and mobility. New applications of ILs include creating new classes of advanced materials, such as a new class of solvogels that are stimuli responsive and reversibly porate via pinned spinodal decomposition and the development of ILs derived from inorganic nanoparticle cores for use as new resin components for diverse materials and coatings applications.
Co-reporter:Feng Yan, Shaomei Yu, Xingwang Zhang, Lihua Qiu, Fuqiang Chu, Jingbi You and Jianmei Lu
Chemistry of Materials 2009 Volume 21(Issue 8) pp:1480
Publication Date(Web):March 26, 2009
DOI:10.1021/cm900098r
Proton-conducting membranes were prepared by polymerization of microemulsions consisting of surfactant-stabilized protic ionic liquid (PIL) nanodomains dispersed in a polymerizable oil, a mixture of styrene and acrylonitrile. The obtained PIL-based polymer composite membranes are transparent and flexible even though the resulting vinyl polymers are immiscible with PIL cores. This type of composite membranes have quite a good thermal stability, chemical stability, tunability, and good mechanical properties. Under nonhumidifying conditions, PIL-based membranes show a conductivity up to the order of 1 × 10−1 S/cm at 160 °C, due to the well-connected PIL nanochannels preserved in the membrane. This type of polymer conducting membranes have potential application in high-temperature polymer electrolyte membrane fuel cells.
Co-reporter:Jie Zhao;Zhenzhen Chen;Hanbin Diao;Fuqiang Chu;Shaomei Yu;Jianmei Lu
Journal of Polymer Science Part A: Polymer Chemistry 2009 Volume 47( Issue 3) pp:746-753
Publication Date(Web):
DOI:10.1002/pola.23190
Abstract
A cationic pyrrole derivative, N-(4-butyl-(1-methylimidazole)) pyrrole bromide (Py-Br) bearing an imidazolium-type ionic liquid moiety was synthesized. Microemulsion polymerization of Py-Br in water/oil microemulsions produced poly(N-(4-butyl-(1-methylimidazole)) pyrrole bromide) (PPy-Br) nanoparticles. The bromide anion of the resultant PPy-Br nanoparticles was exchanged in water with different anions, including BF and PF to produce new nanoparticles bearing different counteranions. The results of thermal analysis indicate that the thermal stability of cationic PPy nanoparticles strongly depends on the nature of counteranion. As an application, water-soluble PPy-Br with fine fluorescence property was used as a new sensor for DNA detection. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 746–753, 2009
Co-reporter:Shaomei Yu, Feng Yan, Xingwang Zhang, Jingbi You, Peiyi Wu, Jianmei Lu, Qingfeng Xu, Xuewei Xia and Guilin Ma
Macromolecules 2008 Volume 41(Issue 10) pp:3389-3392
Publication Date(Web):April 29, 2008
DOI:10.1021/ma8003696
Co-reporter:Jingyue Zhu, Dan Xu, Cancan Wang, Wenjing Qian, Jun Guo, Feng Yan
Carbon (May 2017) Volume 115() pp:
Publication Date(Web):May 2017
DOI:10.1016/j.carbon.2016.12.084
This work reports a facile strategy for the preparation of Nitrogen-doped porous carbons via carbonization of a mixture containing ferric citrate (FC) and ammonium chloride (NH4Cl). FC provides carbon and iron element sources, while ammonium chloride acts as both the porogen and nitrogen dopant during the carbonization process. The formed hierarchical porous structures facilitate the ion diffusion/transport, and nitrogen-doping provides more active sites, which contribute to both oxygen reduction reaction (ORR) and supercapacitor applications. Compared with KOH and NaCl, the utilization of NH4Cl as porogen shows the best ORR performance in this work might due to the dual functions of NH4Cl. Ferric citrate-NH4Cl carbonized at 700 °C exhibits good capacity of 242 F g−1 and stability in 6 M KOH at a current density of 1 A g−1. Since both FC and NH4Cl are cheap and easily available, this work provides a facile and effective method to obtain carbons with superb electrochemical performances.Figure optionsDownload full-size imageDownload high-quality image (156 K)Download as PowerPoint slide
Co-reporter:Jianmei Lu, Feng Yan, John Texter
Progress in Polymer Science (May 2009) Volume 34(Issue 5) pp:431-448
Publication Date(Web):1 May 2009
DOI:10.1016/j.progpolymsci.2008.12.001
Ionic liquids (ILs) are continuing as important media in which to effect various kinds of polymerizations, and it is particularly noteworthy that ionic polymerizations are being developed in IL solvents and that atom transfer radical polymerization (ATRP) catalysts are being attached to ILs to make them more easily recoverable in living polymerizations. In addition, the number of polymerizable ILs is steadily increasing, and ionic liquid polymers of polymerizable ionic liquid monomers have been produced as exotic polyelectrolytes. ILs are being used as plasticizers of various kinds of polymers and as key components in new classes of polymer gels. Polymers and inorganic substrates are being used to support ILs through covalent binding of the ILs, in which case the properties of the IL are modified to some extent, and polymer membranes and porous materials absorb ILs with concomitant changes in ionic conductivity and mobility. New applications of ILs include creating new classes of advanced materials, such as a new class of solvogels that are stimuli responsive and reversibly porate via pinned spinodal decomposition and the development of ILs derived from inorganic nanoparticle cores for use as new resin components for diverse materials and coatings applications.
Co-reporter:Xiao Wu, Lihua Qiu, Zhenzhong Yang, Feng Yan
Applied Catalysis A: General (20 May 2014) Volume 478() pp:
Publication Date(Web):20 May 2014
DOI:10.1016/j.apcata.2014.03.026
•Polymer nanotubes were synthesized via cationic polymerization.•Polymer nanotubes were surface functionalized with imidazolium cations.•AuNPs and Au-AgNPs can be grown on the polymer nanotube surface.•The synthesized nanohybrids are suitable substrate for surface-enhanced Raman spectra.•The resultant nanohybrids are effective catalysts in the reduction of 4-nitrophenol.A facile and effective procedure for the preparation of poly(divinybenzene-co-chloromethylstyrene) (poly(DVB-co-VBC)) nanotube/Au-Ag nanoparticle composite (NT-Im-Au-Ag) via using covalently attached imidazolium as linkers was reported. The approach involves the surface functionalization of poly(DVB-co-VBC) NTs with imidazolium cation, anion-exchange with Au precursor (HAuCl4) and followed by the reduction of metal ions. The obtained NT-Im-Au nanoparticle composite was further used as the seeds to produce NT-Im-Au-Ag nanoparticle composite. The morphology and optical properties of the produced nanohybrids were characterized by transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy. The as-prepared NT-Im-Au-Ag nanohybrids show an extremely suitable substrate for surface-enhanced Raman spectroscopy (SERS) with a high enhancement factor of 6.7 × 107, enabling the detection of 10−12 M Rhodamine 6G solution. The catalytic performance of NT-Im-Au-Ag nanohybrids was studied by the reduction of 4-nitrophenol with NaBH4 as a reducing agent. Their reaction rate constant was calculated according to the pseudo-first-order reaction equation.Download high-res image (195KB)Download full-size image
Co-reporter:Fei Chen, Yongyuan Ren, Jiangna Guo and Feng Yan
Chemical Communications 2017 - vol. 53(Issue 10) pp:NaN1598-1598
Publication Date(Web):2016/12/21
DOI:10.1039/C6CC08924K
Thermo- and electro-dual responsive poly(ionic liquid) (PIL) based electrolytes were synthesized by co-polymerization of N-isopropylacrylamide (NIPAM) with (or without) 3-butyl-1-vinyl-imidazolium bromide ([BVIm][Br]) using diallyl-viologen (DAV) as both the cross-linking agent and electrochromic material.
Co-reporter:Wenjing Qian, John Texter and Feng Yan
Chemical Society Reviews 2017 - vol. 46(Issue 4) pp:NaN1159-1159
Publication Date(Web):2017/02/09
DOI:10.1039/C6CS00620E
We review recent works on the synthesis and application of poly(ionic liquid)s (PILs). Novel chemical structures, different synthetic strategies and controllable morphologies are introduced as a supplement to PIL systems already reported. The primary properties determining applications, such as ionic conductivity, aqueous solubility, thermodynamic stability and electrochemical/chemical durability, are discussed. Furthermore, the near-term applications of PILs in multiple fields, such as their use in electrochemical energy materials, stimuli-responsive materials, carbon materials, and antimicrobial materials, in catalysis, in sensors, in absorption and in separation materials, as well as several special-interest applications, are described in detail. We also discuss the limitations of PIL applications, efforts to improve PIL physics, and likely future developments.
Co-reporter:Haigang Zhang, Lihua Qiu, Dan Xu, Wei Zhang and Feng Yan
Journal of Materials Chemistry A 2014 - vol. 2(Issue 7) pp:NaN2226-2226
Publication Date(Web):2013/11/29
DOI:10.1039/C3TA14571A
Liquid electrolyte DSSCs using 100% water as the solvent and I−/I3− as the redox couple were fabricated. The effect of ionic surfactants on water based DSSCs was investigated by electrochemical impedance spectroscopy (EIS) and contact angle measurements. Addition of surfactant to the aqueous electrolyte improved the interfacial contact between the aqueous electrolyte and the TiO2 films while decreased the interface recombination resistance. With the addition of 0.2 wt% of N,N,N-trimethyl-3-(perfluorooctylsulfonamido)propan-1-aminium iodide (FC-134) in the aqueous electrolyte, average overall power conversion efficiencies of 3.96% and 4.66% were obtained under the simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2 and 50 mW cm−2, respectively. These results show a feasible scheme towards the fabrication of greener and more efficient aqueous DSSCs.
Co-reporter:Chengzhen Shi, Shichao Li, Wei Zhang, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2013 - vol. 1(Issue 44) pp:NaN13962-13962
Publication Date(Web):2013/09/12
DOI:10.1039/C3TA12712E
A new family of organic ionic plastic crystals (OIPCs) based on bis-quaternary ammonium cations was synthesized and characterized. The synthesized bis-quaternary ammonium salts with bis(trifluoromethanesulfonyl) imide (TFSI−) anions exhibit plastic crystal properties as determined by differential scanning calorimetry (DSC). The high ionic conductivity of the compounds in the solid-state indicated that this new family of OIPCs can be promising solid-state electrolytes for electrochemical devices. Cyclic voltammetry characterization of OIPCs in the liquid-state revealed their wide electrochemical windows and highly reversible lithium metal electrodeposition properties.
Co-reporter:Huizi Cao-Cen, Jie Zhao, Lihua Qiu, Dan Xu, Qing Li, Xiaojian Chen and Feng Yan
Journal of Materials Chemistry A 2012 - vol. 22(Issue 25) pp:NaN12850-12850
Publication Date(Web):2012/05/02
DOI:10.1039/C2JM31551C
Organic ionic crystals carrying 4-cyano-4′-hydroxybiphenyl and imidazolium units were synthesized and applied as the electrolytes for dye-sensitized solar cells (DSSCs). The fabricated all-solid-state DSSCs achieved a cell efficiency of ∼5.11% at 55 °C under the simulated air mass 1.5 solar spectrum illuminations at 100 mW cm−2 because of the enhanced light harvesting capability of the electrolyte. To further improve the cell efficiency, 1-propyl-3-methylimidazolium iodine (PMII), was added into the electrolytes as a crystal growth inhibitor. These fabricated devices showed an enhanced power conversion efficiency (PCE) of ∼6.55% at 45 °C under the simulated air mass 1.5 solar spectrum illuminations at 50 mW cm−2, and a superior long-term stability. The cyanobiphenyl-functionalized ionic crystal based electrolytes have expanded our vision to explore new types of all-solid-state electrolytes for high-efficiency DSSCs.
Co-reporter:Jie Zhao, Baoquan Sun, Lihua Qiu, Huizi Caocen, Qing Li, Xiaojian Chen and Feng Yan
Journal of Materials Chemistry A 2012 - vol. 22(Issue 35) pp:
Publication Date(Web):
DOI:10.1039/C2JM32607H
Co-reporter:Fuqiang Chu, Bencai Lin, Bo Qiu, Zhihong Si, Lihua Qiu, Zongzong Gu, Jianning Ding, Feng Yan and Jianmei Lu
Journal of Materials Chemistry A 2012 - vol. 22(Issue 35) pp:NaN18417-18417
Publication Date(Web):2012/07/27
DOI:10.1039/C2JM32787B
Polybenzimidazole (PBI)/H3PO4/zwitterion-coated silica nanoparticle hybrid proton conducting membranes for anhydrous proton-exchange membrane application were synthesized and characterized. Fluorine-containing PBI was synthesized via the condensation polymerization of 3,3-diaminobenzidine and 2-bis(4-carboxyphenyl) hexafluoropropane in poly(phosphoric acid) at 170 °C. Zwitterion-coated silica nanoparticles were synthesized via the hydrolysis and polycondensation of zwitterionic organosiloxane, and applied as the additive for the PBI-based hybrid proton conducting membranes. The synthesized phosphoric acid doped polymeric composite membranes were transparent, flexible and showed high proton conductivities of up to 1 × 10−2 S cm−1 at 160 °C under anhydrous conditions. Addition of zwitterion-coated silica nanoparticles to the PBI membrane dramatically increased the phosphoric acid doping capacity, and slightly improved the chemical stability of the composite membranes. Compared with pure PBI membranes, zwitterion-coated SiO2 nanoparticles are effective in preventing the release of the phosphoric acid component from the composite membranes. These properties enable this type of hybrid membrane to be suitable for high-temperature polymer electrolyte membrane fuel cells.
Co-reporter:Jie Zhao, Xiaojuan Shen, Feng Yan, Lihua Qiu, Shuittong Lee and Baoquan Sun
Journal of Materials Chemistry A 2011 - vol. 21(Issue 20) pp:NaN7330-7330
Publication Date(Web):2011/04/04
DOI:10.1039/C1JM10346F
Photochemically stable poly(ionic liquids) (poly(ILs)) including poly(1-butyl-3-vinylimidazolium bromide) ([PBVIm][Br]) and poly(1-butyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide) ([PBVIm][TFSI]) were synthesized and dissolved in the room temperature ionic liquids (ILs) to form quasi-solid-state electrolytes for dye-sensitized solar cells (DSSCs), without using any volatile organic solvent. DSSCs based on IL/[PBVIm][TFSI] gel electrolyte yielded a power conversion efficiency of 4.4% under a simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2. The superior long-term stability of fabricated DSSCs indicated that the DSSCs based on solvent-free IL/poly(ILs) gel electrolytes could overcome the drawbacks of cells containing volatile solvents.
Co-reporter:Xiaojian Chen, Jie Zhao, Jinyu Zhang, Lihua Qiu, Dan Xu, Haigang Zhang, Xiaoyuan Han, Baoquan Sun, Gaohui Fu, Ye Zhang and Feng Yan
Journal of Materials Chemistry A 2012 - vol. 22(Issue 34) pp:NaN18024-18024
Publication Date(Web):2012/07/13
DOI:10.1039/C2JM33273F
Bis-imidazolium based poly(ionic liquid), poly(1-butyl-3-(1-vinylimidazolium-3-hexyl)-imidazolium bis(trifluoromethanesulfonyl)imide) (Poly[BVIm][HIm][TFSI]) and mono-imidazolium based poly(ionic liquid), poly(1-butyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide) (Poly[BVIm][TFSI]), were synthesized and dissolved in room temperature ionic liquids (ILs) to form quasi-solid-state electrolytes for dye-sensitized solar cells (DSSCs), without using any volatile organic solvent. Compared with mono-imidazolium based poly[BVIm][TFSI], bis-imidazolium based poly[BVIm][HIm][TFSI] electrolytes showed a higher thermal stability and conductivity due to the charge transport networks formed in the gel electrolytes via the π–π stacked imidazolium rings. The DSSCs based on the poly[BVIm][HIm][TFSI] gel electrolyte showed a superior long-term stability and yielded a power conversion efficiency of 5.92% under the simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2. This study offered a feasible method to fabricate quasi-solid-state DSSCs in future practical applications.
Co-reporter:Congtao Pan;Lihua Qiu;Yingjing Peng
Journal of Materials Chemistry A 2012 - vol. 22(Issue 27) pp:NaN13584-13584
Publication Date(Web):2012/06/19
DOI:10.1039/C2JM31973J
A polymerizable ionic liquid (IL), 1-butyl-3-vinylimidazolium bromide ([Bvim][Br]), was synthesized and copolymerized with acrylonitrile to produce poly(1-butyl-3-vinylimidazolium bromide-co-acrylonitrile) (PBA). Carbonization of PBA yielded carbon materials. The carbon yield, nitrogen content and nanostructure of carbon materials are highly dependent on the IL molar ratio in the co-polymers. The synthesized PBA was anion-exchanged with Pt precursor (H2PtCl6) to form [PBA][PtCl6]. Carbonization of [PBA][PtCl6] produced nitrogen-doped carbon–Pt nanohybrids, which showed a high catalytic activity and stability for electrocatalytic oxidation of methanol. The present study provided a novel method for the development of high performance electrocatalysts based on nitrogen-doped carbon–Pt or other noble metals and their alloys for fuel cells or electrochemical sensors.
Co-reporter:Bo Qiu, Bencai Lin, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2012 - vol. 22(Issue 3) pp:NaN1045-1045
Publication Date(Web):2011/11/14
DOI:10.1039/C1JM14331J
Alkaline imidazolium-type ionic liquids (ILs) and quaternary ammonium salt functionalized alkaline anion-exchange membranes (AEMs), with the same ion exchange capacity (IEC), were synthesized via in situ cross-linking of styrene, acrylonitrile, 1-methyl-3-(4-vinylbenzyl)imidazolium chloride ([MVBIm][Cl]), and N,N,N-trimethyl-1-(4-vinylphenyl) methanaminium chloride ([TMVPMA][Cl]), respectively. The water uptake, swelling ratio, conductivity, and alkaline stability of resultant cross-linked copolymer membranes were investigated. Both types of copolymer membranes exhibit hydroxide conductivity above 10−2 S cm−1 at room temperature. Alkaline imidazolium-type IL functionalized membranes showed an excellent chemical stability of up to 1000 h without obvious loss of ion conductivity, whereas the membranes based on quaternary ammonium salts degraded in high pH solution because of nucleophillic substitution on quaternary ammonium cations. The results of this study suggest that the AEMs based on alkaline imidazolium-type ILs are expected to promote the widespread use of alkaline fuel cells.
Co-reporter:Qing Li, Xiaojian Chen, Jie Zhao, Lihua Qiu, Yueguang Zhang, Baoquan Sun and Feng Yan
Journal of Materials Chemistry A 2012 - vol. 22(Issue 14) pp:NaN6679-6679
Publication Date(Web):2012/02/24
DOI:10.1039/C2JM16850B
An organic ionic plastic crystal, 1-ethyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (P12TFSI), was synthesized and doped with a room temperature ionic liquid, 1-propyl-3-methylimidazolium iodide (PMII). The prepared PMII/P12TFSI solid-state electrolytes were employed for dye-sensitized solar cells (DSSCs), without using any volatile organic solvent. The fabricated solid-state DSSCs yielded a power conversion efficiency of 5.12% under simulated air mass 1.5 solar spectrum illuminations at 50 mW cm−2. The superior long-term stability of the fabricated solid-state DSSCs indicated that the synthesized PMII/P12TFSI solid-state electrolytes could overcome the drawbacks of cells containing volatile solvents.
Co-reporter:Bo Qiu, Congtao Pan, Wenjing Qian, Yingjing Peng, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2013 - vol. 1(Issue 21) pp:NaN6378-6378
Publication Date(Web):2013/04/04
DOI:10.1039/C3TA10774D
Nitrogen-doped mesoporous carbon materials are prepared via carbonization of a room temperature ionic liquid, 1-butyl-3-methylimidazolium dicyanamide (BMIMdca), using a mesoporous silica template (SBA-15). The nitrogen content and nanostructure of the resultant carbon materials are highly dependent on the carbonization temperature. The produced porous carbon materials were further applied as the electrode materials for supercapacitors. The porous structure and nitrogen functionalities enable carbon materials with a specific capacitance of 210 F g−1 at a current density of 1 A g−1 in a 6 M KOH aqueous solution. Furthermore, the nitrogen-doped porous carbon materials maintain a high capacitance retention capability (∼95%) after 1000 cycles at a current density of 1 A g−1, indicating that this kind of nitrogen-doped carbon material originated from room temperature ionic liquids is a promising electrode material for high-performance supercapacitors. These results may provide a facile synthesis of sulfur and nitrogen or multi-element doped porous carbon materials originated from ionic liquids for supercapacitors.
Co-reporter:Dan Xu, Haigang Zhang, Xiaojian Chen and Feng Yan
Journal of Materials Chemistry A 2013 - vol. 1(Issue 38) pp:NaN11941-11941
Publication Date(Web):2013/08/05
DOI:10.1039/C3TA12031G
CoII/III redox couples and their derivatives have been extensively studied and applied as redox mediators for high efficiency organic solvent DSSCs. However, CoII/III complex redox mediator-based ionic liquid electrolyte DSSCs have not been studied so far due to the poor solubility of most CoII/III complexes in ionic liquid electrolytes. Herein, an imidazolium functionalized cobalt tris(bipyridyl) complex redox mediator ([Co((MeIm-Bpy)PF6)3]2+/3+) (((MeIm-Bpy)PF6)3 = 3,3′-(2,2′-bipyridine-4,4′-diyl-bis(methylene))bis(1-methyl-1H-imidazol-3-ium)hexafluorohosphate) with high redox potential and good solubility in ionic liquid electrolyte has been synthesized and applied in ionic liquid electrolyte DSSCs. Using the dye N719 as the photosensitizer, overall power conversion efficiencies of 7.37% and 8.29% are achieved in binary ionic liquid-based electrolyte under 1.5 solar spectrum illumination at 100 and 50 mW cm−2, respectively. Both values are considerably higher than those of the I−/I3− redox couple-based ionic liquid electrolyte.
Co-reporter:Yingjing Peng, Xiao Wu, Lihua Qiu, Changhai Liu, Suidong Wang and Feng Yan
Journal of Materials Chemistry A 2013 - vol. 1(Issue 32) pp:NaN9263-9263
Publication Date(Web):2013/05/24
DOI:10.1039/C3TA11676J
A facile and effective procedure for the synthesis of PtAu nanoparticles–carbon (PtAu–C) via the carbonization of triethoxysilane-derivatized ionic liquids is reported. A triethoxysilyl-functionalized ionic liquid, 1-methyl-3-[3-(triethoxysilyl)propyl]imidazolium chloride ([Si-pim][Cl]) was synthesized and anion-exchanged with a Pt precursor (H2PtCl6) and a Au precursor (HAuCl4) to form [Si-pim][PtCl6]x[AuCl4]y (the suffixes x and y represent the relative molar ratios of Pt and Au in the feed, respectively). The carbonization of [Si-pim][PtCl6]x[AuCl4]y, followed by hydrofluoric acid (HF) etching, produced PtxAuy–C hybrids. The composition of the PtxAuy alloy NPs can be controlled simply by adjusting the feed ratio in the metal precursor solution. The electrocatalytic properties of the prepared PtxAuy–C hybrids were determined by the composition of the alloy NPs. The resultant Pt–C hybrids show high electroactivity towards methanol oxidation in an acidic medium, while Pt4Au1–C shows high activity towards the reduction of 4-nitrophenol. The present study provides a highly efficient approach for the development of high-performance noble metals and their alloy-based catalysts.
Co-reporter:Xiaojian Chen, Dan Xu, Lihua Qiu, Shichao Li, Wei Zhang and Feng Yan
Journal of Materials Chemistry A 2013 - vol. 1(Issue 31) pp:NaN8765-8765
Publication Date(Web):2013/05/21
DOI:10.1039/C3TA11521F
The imidazolium functionalized stable organic radical 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO), and 1-methyl-3-(2-oxo-2-(2,2,6,6-tetramethyl-1-oxyl-4-piperidoxyl) butyl)imidazolium bis(trifluoromethanesulfonyl) imide ([MeIm-TEMPO][TFSI]), were synthesized and characterized. The prepared [MeIm-TEMPO][TFSI]/1-propyl-3-methylimidazolium iodide (PMII) hybrid redox couple showed negligible absorption in the visible region and higher redox potential as compared with the iodide/triiodide (I−/I3−) redox couple. The resulting dye-sensitized solar cells (DSSCs) containing the imidazolium functionalized TEMPO/PMII hybrid redox couple in combination with organic dye (D205) exhibited average overall power conversion efficiencies of 8.2% and 9.1% under simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2 and 50 mW cm−2, respectively, which are higher than that of the traditional PMII/I2 based electrolyte, probably due to the enhancement of the Voc and Jsc values of the hybrid electrolytes.
Co-reporter:Dan Xu, Chengzhen Shi, Lei Wang, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2014 - vol. 2(Issue 25) pp:NaN9811-9811
Publication Date(Web):2014/04/22
DOI:10.1039/C4TA01255K
The charge recombination at the TiO2 photoelectrode/electrolyte interface plays a crucial role in determining the efficiency of solid-state dye-sensitized solar cells (DSSCs) because of the poor interface contact at the TiO2 photoelectrode/electrolyte interface. In this work, we report the surface co-grafting of surfactants onto the surface of the TiO2 photoelectrode, and their effects on the photovoltaic performance of solid-state DSSCs. Three ionic surfactants, including anionic surfactants, sodium 2-ethylhexyl sulfosuccinate (AOT) and chenodeoxycholic acid (CDCA), and a cationic surfactant, dodecyltrimethylammonium bromide (DTAB), were applied for the modification of the TiO2 photoelectrode/electrolyte interface. The results show that co-grafting of surfactants AOT or CDCA on the TiO2 photoelectrode surface, and post heat treatment (above the melting point of solid-state electrolytes) could drastically improve the interfacial contact properties of the TiO2 photoelectrode/electrolyte interface, increase the penetration of the electrolytes into the porous TiO2 photoelectrode, and thus enhance the photovoltaic performances of the solid-state electrolyte DSSCs. With the surface modification of AOT/N719, the succinonitrile based solid-state DSSCs exhibited superior long-term stability, and showed power conversion efficiencies of 6.75% and 7.92% under 1.5 solar spectrum illuminations at 100 and 50 mW cm−2, respectively.
Co-reporter:Zhihong Si, Zhe Sun, Fenglou Gu, Lihua Qiu and Feng Yan
Journal of Materials Chemistry A 2014 - vol. 2(Issue 12) pp:NaN4421-4421
Publication Date(Web):2014/01/06
DOI:10.1039/C3TA15178F
Solvent processable anion exchange membranes (AEMs) containing imidazolium cation and poly(arylene ether sulfone) side chains were prepared via the ionization of poly(4-vinylbenzyl chloride)-graft-poly(arylene ether sulfone) copolymers, and followed by anion exchange with hydroxide ions. The ionized copolymers produced ductile, transparent membranes which possess a relatively high ionic conductivity (up to 1.6 × 10−2 S cm−1 at room temperature). The yielded membranes are soluble in polar aprotic solvents, such as DMSO and DMF, while insoluble in water and methanol. The synthesized AEMs show good alkaline stability in 1 M KOH at 60 °C for 20 days, as well as high dimensional and thermal stability. These results should pave way to the practical application of this kind of AEM in alkaline fuel cells.
Co-reporter:Jiangna Guo, Chao Yuan, Mingyu Guo, Lei Wang and Feng Yan
Chemical Science (2010-Present) 2014 - vol. 5(Issue 8) pp:NaN3266-3266
Publication Date(Web):2014/04/28
DOI:10.1039/C4SC00864B
A robust and flexible polymer velcro was synthesized via surface modification of poly(ionic liquid) (PIL) membranes with ferrocene (Fc) and β-cyclodextrin (β-CD) moieties, which act as the hooks and loops, respectively. Through molecular recognition between the β-CD and Fc moieties, the prepared PIL-β-CD and PIL-Fc membranes adhered with each other under mechanical compression, without the use of any curing agents. This polymer velcro exhibits strong adhesion in air and in aqueous solutions (including acidic and basic water, and artificial seawater), and could be unfastened and fastened by mechanical and chemical means. Due to the intrinsic ionic conductivity of the PIL membranes, our polymer velcro possesses an unprecedented feature, that the adhesion reversibility can be electrochemically controlled by the applied potential.
Co-reporter:Jie Zhao, Feng Yan, Lihua Qiu, Yueguang Zhang, Xiaojian Chen and Baoquan Sun
Chemical Communications 2011 - vol. 47(Issue 41) pp:NaN11518-11518
Publication Date(Web):2011/09/23
DOI:10.1039/C1CC15069C
Benzimidazolyl functionalized ionic liquids were synthesized and applied as additives for dye-sensitized solar cells. The fabricated devices show an overall power conversion efficiency of ∼7.79% under AM 1.5 radiation (50 mW cm−2), and an excellent long-term stability.
Co-reporter:Lihua Qiu, Baoqiang Liu, Yingjing Peng and Feng Yan
Chemical Communications 2011 - vol. 47(Issue 10) pp:NaN2936-2936
Publication Date(Web):2011/01/24
DOI:10.1039/C0CC04865H
Polypyrrole
nanotubes (PPyNTs)/Pt nanoparticle hybrids were synthesized by using covalently attached imidazolium-type ionic liquids (ILs) as linkers. The resultant Pt/ILs/PPyNTs hybrids exhibited high electrocatalytic activity in electrocatalytic oxidation of methanol.
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![Phenol, 4,4'-[9,9-bis(6-bromohexyl)-9H-fluorene-2,7-diyl]bis-](/data/chemimg/3719000/1351954-77-2.png)
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![Benzenesulfonic acid, 4-[2-[4-(dimethylamino)phenyl]diazenyl]-, ion(1-)](/data/chemimg/3780200/20215-37-6_b.png)
![Benzoic acid, 2-[(2-methyl-1-oxo-2-propenyl)amino]-](http://img.cochemist.com/ccimg/7700/7600-39-7.png)
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