Co-reporter:Na Song, Siqi Cui, Xingshuang Hou, Peng Ding, and Liyi Shi
ACS Applied Materials & Interfaces November 22, 2017 Volume 9(Issue 46) pp:40766-40766
Publication Date(Web):November 10, 2017
DOI:10.1021/acsami.7b09240
High thermal conductive nanofibrillated cellulose (NFC) hybrid films based on nanodiamond (ND) were fabricated by a facile vacuum filtration technique. In this issue, the thermal conductivity (TC) on the in-plane direction of the NFC/ND hybrid film had a significant enhancement of 775.2% at a comparatively low ND content (0.5 wt %). The NFC not only helps ND to disperse in the aqueous medium stably but also plays a positive role in the formation of the hierarchical structure. ND could form a thermal conductive pathway in the hierarchical structures under the intermolecular hydrogen bonds. Moreover, the hybrid films composed of zero-dimensional ND and one-dimensional NFC exhibit remarkable mechanical properties and optical transparency. The NFC/ND hybrid films possessing superior TC, mechanical properties, and optical transparency can open applications for portable electronic equipment as a lateral heat spreader.Keywords: hierarchical structure; nanodiamond; nanofibrillated cellulose; optical transparency; thermal conductivity;
Co-reporter:Yafei Zhao;Lan Mu;Yongxiang Su;Liyi Shi;Xin Feng
Journal of Materials Chemistry B 2017 vol. 5(Issue 31) pp:6233-6236
Publication Date(Web):2017/08/09
DOI:10.1039/C7TB01678F
We designed a unique and novel bio-nanoplatform based on Pt–Ni nanoframes (PNnf) functionalized with carbon dots via the EDC/NHS coupling chemistry. The PNnf with open three-dimensional surfaces exhibited excellent water solubility after polyethylenimine modification. Due to low cytotoxicity and excellent biocompatibility, the bio-nanoplatforms were firstly used for MCF-7 cell imaging in vitro. More importantly, the design strategy can be readily generalized to facilitate other multi-functional bio-nanoplatforms for biological and biomedical applications.
Co-reporter:Yamin Feng;Qingbo Xiao;Yanhui Zhang;Fujin Li;Yanfang Li;Chunyan Li;Qiangbin Wang;Liyi Shi;Hongzhen Lin
Journal of Materials Chemistry B 2017 vol. 5(Issue 3) pp:504-510
Publication Date(Web):2017/01/18
DOI:10.1039/C6TB01961G
The achievement of efficient near-infrared (NIR) luminescence of lanthanide ions in a paramagnetic nanoparticle (NP) host is highly desirable to optimize the performance of multimodal bioprobes. Herein, we present a facile coprecipitation method to prepare highly uniform NaHoF4:Nd3+ nanoplates. Upon NIR excitation at 785 nm, efficient NIR luminescence of Nd3+ can be obtained from the paramagnetic NaHoF4 hosts. More interestingly, due to energy transfer from the excited state of Nd3+ to the adjacent Ho3+, NIR emission at around 1200 nm from Ho3+ ions is also observed. The r2 value of NaHoF4:Nd3+ NPs reaches 143.7 s−1 mM−1 at a high magnetic field of 11.7 T. By modifying with hydrophilic alpha-cyclodextrin, the NaHoF4:Nd3+ NPs were further successfully applied for the NIR luminescent/T2-weighted MR dual-modal in vivo imaging of nude mice, high contrast NIR imaging of the liver and T2-weighted MR imaging of stem cells in the mouse brain using the NaHoF4:Nd3+ NPs as multimodal bioprobes.
Co-reporter:Ruoyan Wei, Zuwu Wei, Lining Sun, Jin Z. Zhang, Jinliang Liu, Xiaoqian Ge, and Liyi Shi
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 1) pp:400
Publication Date(Web):December 24, 2015
DOI:10.1021/acsami.5b09132
Iron ion (Fe3+) which is the physiologically most abundant and versatile transition metal in biological systems, has been closely related to many certain cancers, metabolism, and dysfunction of organs, such as the liver, heart, and pancreas. In this Research Article, a novel Nile red derivative (NRD) fluorescent probe was synthesized and, in conjunction with polymer-modified core–shell upconversion nanoparticles (UCNPs), demonstrated in the detection of Fe3+ ion with high sensitivity and selectivity. The core–shell UCNPs were surface modified using a synthesized PEGylated amphiphilic polymer (C18PMH-mPEG), and the resulting mPEG modified core–shell UCNPs (mPEG-UCNPs) show good water solubility. The overall Fe3+-responsive upconversion luminescence nanostructure was fabricated by linking the NRD to the mPEG-UCNPs, denoted as mPEG-UCNPs-NRD. In the nanostructure, the core–shell UCNPs, NaYF4:Yb,Er,Tm@NaGdF4, serve as the energy donor while the Fe3+-responsive NRD as the energy acceptor, which leads to efficient luminescence resonance energy transfer (LRET). The mPEG-UCNPs-NRD nanostructure shows high selectivity and sensitivity for detecting Fe3+ in water. In addition, benefited from the good biocompatibility, the nanostructure was successfully applied for detecting Fe3+ in living cells based on upconversion luminescence (UCL) from the UCNPs. Furthermore, the doped Gd3+ ion in the UCNPs endows the mPEG-UCNPs-NRD nanostructure with effective T1 signal enhancement, making it a potential magnetic resonance imaging (MRI) contrast agent. This work demonstrates a simple yet powerful strategy to combine metal ion sensing with multimodal bioimaging based on upconversion luminescence for biomedical applications.Keywords: Bioimaging; Fe3+ sensing; MR imaging; Nile red derivative (NRD); Upconversion luminescence nanostructure
Co-reporter:Wei Yan, Ling Wang, Chang Chen, Dan Zhang, Ai-Jun Li, Zheng Yao, Li-Yi Shi
Electrochimica Acta 2016 Volume 188() pp:230-239
Publication Date(Web):10 January 2016
DOI:10.1016/j.electacta.2015.11.146
•NGHMs were constructed using PSMs as template and melamine as nitrogen source.•NGHMs exhibited high catalytic activity towards ORR.•NGHMs displayed a comparable ORR limiting current density to JM 40 wt% Pt/C.•ORR on NGHMs electrode was dominated by 4e− pathway in a wide potential range.Nitrogen-doped graphene hollow microspheres (NGHMs) were constructed, using polystyrene microspheres (PSMs) as the sacrificial template. Negatively charged graphene oxide nanosheets (GONs) were assembled onto sulfonated PSMs with the aid of poly(ethyleneimine) through electrostatic interaction. NGHMs were obtained by pyrolysis the mixture of melamine and GON-wrapped PSMs under a nitrogen atmosphere. During the pyrolysis, the removal of PSMs and reduction of GONs and incorporation of heteroatoms were realized simultaneously. The nitrogen atomic percentage in NGHMs reached 7.13%, and sulfur content was also detected. The prepared NGHMs exhibited high catalytic activity toward oxygen reduction reaction (ORR) in alkaline solution with a comparable limiting current density to JM 40 wt% Pt/C. The ORR on NGHMs electrode was dominated by the four-electron pathway in a wide potential range with long-term stability and high fuel selectivity. The enhanced electrocatalytic performance of NGHMs could be ascribed not only to the high nitrogen content, but also to the hollow sphere architecture. Moreover, the nitrogen precursor, melamine, increased the percentage of graphitic-N and prevented hollow spheres from aggregation, which also helped to improve the catalytic activity of NGHMs.
Co-reporter:Linbo Shao, Liyi Shi, Xuheng Li, Na Song, Peng Ding
Composites Science and Technology 2016 Volume 135() pp:83-91
Publication Date(Web):27 October 2016
DOI:10.1016/j.compscitech.2016.09.013
In this work, we reported a synergistic effect of boron nitride nanosheets (BNNSs) with graphene in the 3D BNNSs/graphene framework (BGF) on the enhancement of thermal conductive properties of polyamide-6 (PA6) composites. The 3D BGF was self-assembled by embedding BNNSs into 3D graphene framework (GF). And the PA6 composites were obtained by in-situ polymerization of PA6 chains in the pores of the 3D framework. The thermal conductivity (TC) of PA6 composites with BGF (1.6 wt% BNNS/6.8 wt% graphene) was improved to 0.891 W·m−1·K−1. This value indicated that additional introduction of 1.6 wt% BNNSs could increase the TC up to 87.6% and 350% compared with the composites containing 6.8 wt% 3D GF (0.475 W·m−1·K−1) and neat PA6 (0.196 W·m−1·K−1), respectively. The high efficiency of BNNSs on the TC enhancement could be attributed to the factors including the unobstructed 3D thermal conductive paths constructed by BNNSs, and the morphology-promoted synergistic effect between BNNSs and graphene nanosheets.Figure optionsDownload full-size imageDownload as PowerPoint slide
Co-reporter:Yanxia Xu, Huifang Li, Xianfu Meng, Jinliang Liu, Lining Sun, Xiaolin Fan and Liyi Shi
New Journal of Chemistry 2016 vol. 40(Issue 4) pp:3543-3551
Publication Date(Web):11 Feb 2016
DOI:10.1039/C5NJ03010B
It is greatly important to seek a fast and sensitive method for the detection of Cu2+ ions because of their vital role in the human body. Fluorescent probes, especially the rhodamine derivatives, have been considered as promising candidates for detection of Cu2+ ions due to their attractive features. However, one problem frequently encountered in rhodamine-based fluorescent probes is that some of them could not distinguish Cu2+ from Hg2+ and these drawbacks limit their application in biological samples. In this paper, a rhodamine B derivative (RBH) was grafted to mesoporous silica coated upconversion nanoparticles (CS-UCNP) to fabricate a new organic–inorganic hybrid nanoprobe. On addition of Cu2+ ions, an emission band at about 580 nm appeared while the intensity of the green emission at about 545 nm of the nanoprobe decreased upon excitation of a 980 nm laser, implying that a luminescence resonance energy transfer (LRET) happened from the CS-UCNP to the RBH–Cu2+ complex. The obtained LRET nanoprobe could detect Cu2+ exclusively even in the presence of Hg2+ with a detection limit of 0.82 μM in absolute ethanol solution. Most importantly, this nanoprobe can be used for monitoring subcellular distribution of Cu2+ in living cells based on upconversion luminescence and downconversion fluorescence.
Co-reporter:Liang Chen;Xiaoying Sun;Jianzhong Hang;Lujiang Jin;Dan Shang;Liyi Shi
Advanced Materials Interfaces 2016 Volume 3( Issue 6) pp:
Publication Date(Web):
DOI:10.1002/admi.201500718
The practical applications of superhydrophobic self-cleaning surfaces have been hampered by poor mechanical durability. Here, a composite coating that possesses excellent superhydrophobicity and robust mechanical durability is fabricated, consisting of a methyl silicone resin and a superhydrophobic silica sol. The coating can be sprayed, dipped, rolled, or flowed onto various substrates, such as glass, metal, paper, and cloth, for large-scale applications. The coating exhibits remarkable superhydrophobicity even after undergoing a finger-wipe test, a knife-scratch test, or 50 abrasion cycles with sandpaper. Moreover, the coating on hard substrates exhibits high rigidity (pencil hardness of 9H), good flexibility (impact resistance of 1 m•kg) and great adhesion (5B).
Co-reporter:Jinghua Liu, Xiaoqian Ge, Lining Sun, Ruoyan Wei, Jinliang Liu and Liyi Shi
RSC Advances 2016 vol. 6(Issue 53) pp:47427-47433
Publication Date(Web):06 May 2016
DOI:10.1039/C6RA06709C
A new kind of carbon dots with an average diameter of approximately 3–5 nm were synthesized using L-lysine. Subsequently, a series of lanthanide complex-functionalized carbon dots were designed and synthesized, denoted as Ln-CDs (Ln = Eu, Sm, Er, Yb, Nd). In addition, by changing the ratio of Eu complexes and carbon dots, four kinds of Eu complex-functionalized carbon dots were also obtained (Eu-CDs-1, Eu-CDs-2, Eu-CDs-3, Eu-CDs-4). The derived nanomaterials were characterized by Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and fluorescence spectroscopy. Upon visible-light excitation, these lanthanide complex-functionalized carbon dots show multicolor visible (Eu; with red, orange, grey and blue colors, respectively) and near-infrared (Sm, Er, Nd, Yb) luminescence (emission covered from 400 nm to 1700 nm spectral region).
Co-reporter:Yanxia Xu, Xianfu Meng, Jinliang Liu, Shuyun Zhu, Lining Sun and Liyi Shi
RSC Advances 2016 vol. 6(Issue 2) pp:1037-1041
Publication Date(Web):18 Dec 2015
DOI:10.1039/C5RA17451A
A new luminescence “Turn-On” nanoplatform based on luminescence resonance energy transfer (LRET) from sodium citrate functionalized upconversion nanoparticles (Cit-UCNPs, energy donor) to single-walled carbon nanohorns (SWCNHs, energy acceptor) was prepared for sensitive detection of acute promyelocytic leukemia (APL). In the presence of the target DNA, a PML/RARα fusion gene of APL, the π–π stacking interaction between the energy donor Cit-UCNPs and energy acceptor SWCNHs weakened and their distance enlarged. Therefore, the luminescence of Cit-UCNPs would be recovered (turn on) due to the inhibition of the LRET process. Based on this fact, a sensitive method was developed for the fluorescence turn on detection of ALP with a detection limit as low as 0.28 nM. To the best of our knowledge, this is the first time that upconversion nanoparticles and single-walled carbon nanohorns were used as a donor–acceptor pair to detect PML/RARα fusion gene sequences through a LRET process.
Co-reporter:Lining Sun, Ying Liu, Song Dang, Zhuyi Wang, Jinliang Liu, Jifang Fu and Liyi Shi
New Journal of Chemistry 2016 vol. 40(Issue 1) pp:209-216
Publication Date(Web):23 Oct 2015
DOI:10.1039/C5NJ02105G
A new 2,2′-bipyridine-4,4′-dicarboxylic acid-functionalized polyhedral oligomeric silsesquioxane (named as bpdc-POSS) was successfully synthesized. Subsequently, six new Ln-bpdc-POSS (Ln = Eu, Tb, Sm, Nd, Yb, Er) hybrid materials covalently linked with lanthanide complexes were prepared, based on the bpdc-POSS material acting as a matrix. The Ln-bpdc-POSS hybrid materials retain the structure of POSS and size distribution approximately 50 nm, and display visible as well as near-infrared luminescence (covered from 450 to 1700 nm wavelength region) under UV/visible light excitation. The Ln-bpdc-POSS materials (Ln = Eu, Tb, Sm, Er, Nd, Yb) were characterized by using wide-angle X-ray powder diffraction, Fourier-transform infrared (FT-IR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), fluorescent spectroscopy and thermogravimetric analysis. The method offers advantages including the ease of synthesis and handling, as well as extending the use of POSS and expanding the field of luminescent inorganic–organic hybrid materials based on lanthanides.
Co-reporter:Xianfu Meng, Yanxia Xu, Jinliang Liu, Lining Sun and Liyi Shi
Analytical Methods 2016 vol. 8(Issue 5) pp:1044-1051
Publication Date(Web):21 Dec 2015
DOI:10.1039/C5AY02792F
A novel fluorescent chemosensor containing two rhodamine B moieties per molecule was synthesized and characterized as an “off–on” fluorescent probe for the detection of copper ions (Cu2+). The crystal structure of the chemosensor was confirmed by X-ray analysis and the recognition mechanism of detecting Cu2+ was proposed with absorption and fluorescence characterization. The chemosensor showed high selectivity and sensitivity and good repetition in sensing Cu2+, and the detection limit is as low as 38.00 nM. In addition, the chemosensor displayed low cytotoxicity as revealed by methyl thiazolyl tetrazolium (MTT) assays and was successfully applied to fluorescence test paper and living cell imaging for detecting Cu2+. Therefore, based on its environmental friendliness and good biocompatibility, the results offered the advantages including the detection of Cu2+ in the environment and bioimaging of intracellular Cu2+.
Co-reporter:Ran Li, Yin Zhao, Ruien Hou, Xin Ren, Shuai Yuan, Yanyan Lou, Zhuyi Wang, Dongdong Li, Liyi Shi
Journal of Photochemistry and Photobiology A: Chemistry 2016 s 319–320() pp: 62-69
Publication Date(Web):15 March 2016
DOI:10.1016/j.jphotochem.2016.01.002
•DSSC photoanode was modified by Al doped TiO2 layers.•The modification enhanced electron transport and suppressed charge recombination.•The electron injection efficiency and collection efficiency were improved.The optimization of charge transfer at the TiO2/dye/electrolyte interface is crucial to the design of dye-sensitized solar cells. In this paper, the Al doped TiO2 layers were coated on the mesoporous TiO2 films by a chemical bath deposition process, followed by sintering at 500 °C. Its performance as the TiO2/dye/electrolyte interface layer was investigated. The analysis results reveals that the Al doped TiO2 coating can reduce the oxygen vacancy-Ti3+ concentrations in the photoanodes significantly, which is beneficial to suppress the back electron transfer process from TiO2 to electrolyte. Furthermore, the electron mobility of the modified photoanodes was increased. Consequently, the dye sensitized solar cells (DSSC) based on the photoanodes modified by Al-doped TiO2 coating show an improvement on both enhancing the electron transport and suppressing the charge recombination process. The dye sensitized solar cell based on the photoanode modified by 1.0 mol% Al-doped TiO2 layer, shows a power conversion efficiency as high as 7.66%, increasing 9.12% compared with the unmodified reference cell. Finally, our works show a facile and scalable technique to further optimize interfacial charge transfer process in dye sensitized solar cells.Download full-size image
Co-reporter:Xieliang Cui, Peng Ding, Nan Zhuang, Liyi Shi, Na Song, and Shengfu Tang
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 34) pp:19068
Publication Date(Web):August 17, 2015
DOI:10.1021/acsami.5b04444
In this work, we reported a synergistic effect of boron nitride (BN) with graphene nanosheets on the enhancement of thermal conductive and mechanical properties of polymeric composites. Here, few layered BN (s-BN) and graphene (s-GH) were used and obtained by liquid exfoliation method. The polystyrene (PS) and polyamide 6 (PA) composites were obtained via solution blending method and subsequently hot-pressing. The experimental results suggested that the thermal conductivity (TC) of the PS and PA composites increases with additional introduction of s-BN. For example, compared with the composites containing 20 wt % s-GH, additional introduction of only 1.5 wt % s-BN could increase the TC up to 38 and 34% in polystyrene (PS) and polyamide 6 (PA) matrix, respectively. Meanwhile, the mechanical properties of the composites were synchronously enhanced. It was found that s-BN filled in the interspaces of s-GH sheets and formed s-BN/s-GH stacked structure, which were helpful for the synchronously improving TC and mechanical properties of the polymeric materials.Keywords: boron nitride; graphene; polymer; solution-exfoliated; thermal conductivity;
Co-reporter:Ruien Hou, Shuai Yuan, Xin Ren, Yin Zhao, Zhuyi Wang, Meihong Zhang, Dongdong Li, Liyi Shi
Electrochimica Acta 2015 Volume 154() pp:190-196
Publication Date(Web):1 February 2015
DOI:10.1016/j.electacta.2014.12.083
Acetyl acetone and its derivatives, 3-butyl-2,4-pentanedione and 3-phenyl-2, 4-pentanedione are investigated as co-adsorbents of photoelectrodes for dye-sensitized solar cells (DSSC). The DSSC based on 3-phenyl-2,4-pentanedione co-adsorbent shows the best photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 67.3%, a short-circuit photocurrent density (JSC) of 15.73 mA cm2, an open-circuit photo-voltage (VOC) of 0.74 V and a fill factor (FF) of 0.69, corresponding to an overall conversion efficiency of 8.07% under the standard global AM 1.5 solar light condition. Electrochemical impedance (EIS) data and open-circuit voltage decay (OCVD) data indicate that the electron lifetime is improved by co-adsorption of 3-phenyl-2,4-pentanedione, it is associated with the 3-phenyl-2,4-pentanedione co-adsorbent forms a protect layer of TiO2 which can inhibit the electron recombination efficiently. The results confirm that the acetyl acetone-typed co-adsorbents with less effect on the adsorption of dye, more hydrophobic structure and stronger electron donating ability, such as 3-phenyl-2,4-pentanedione, can improve the performance of DSSC.
Co-reporter:Qian Liu, Lifang Wei, Shuai Yuan, Xin Ren, Yin Zhao, Zhuyi Wang, Meihong Zhang, Liyi Shi, Dongdong Li and Aijun Li
RSC Advances 2015 vol. 5(Issue 88) pp:71778-71784
Publication Date(Web):14 Aug 2015
DOI:10.1039/C5RA13135A
Nickel oxide as one of the few p-type semiconductors has great potential applications in the construction of photovoltaics and solar fuel production devices. The present work focuses on understanding the surface structure of NiO by controlling the surface Ni3+ species (e.g. NiO(OH)) that influence the electrochemical process at the NiO/liquid electrolyte interface. With the aid of the Mott–Schottky method, electrochemical impedance spectroscopy and photocurrent–voltage correlation testing, various NiO surface structures were correlated with observed changes in the band energies, energetic distributions of the trap states densities, charge interface transfer, charge transport, and as a result the p-type DSSC device performances. The primary results demonstrate that the NiO(OH) species act as recombination centers and cause worse interface recombination. Furthermore, we also report an effective way of reducing the surface NiO(OH) structures by a Ni(CH3COOH)2 post-treatment method, resulting in a 31.3% increase in the photovoltaic performance. Our work provides good guidance for the design and fabrication of solar energy-related devices employing NiO electrodes.
Co-reporter:Lining Sun;Yannan Qiu;Tao Liu;Jing Feng;Wei Deng;Liyi Shi
Luminescence 2015 Volume 30( Issue 7) pp:1071-1076
Publication Date(Web):
DOI:10.1002/bio.2860
Abstract
We used the synthesized dinaphthylmethane (Hdnm) ligand whose absorption extends to the visible-light wavelength, to prepare a family of ternary lanthanide complexes, named as [Ln(dnm)3phen] (Ln = Sm, Nd, Yb, Er, Tm, Pr). The properties of these complexes were investigated by Fourier transform infrared (FT-IR) spectroscopy, diffuse reflectance (DR) spectroscopy, thermogravimetric analyses, and excitation and emission spectroscopy. Generally, excitation with visible light is much more advantageous than UV excitation. Importantly, upon excitation with visible light (401–460 nm), the complexes show characteristic visible (Sm3+) as well as near-infrared (Sm3+, Nd3+, Yb3+, Er3+, Tm3+, Pr3+) luminescence of the corresponding lanthanide ions, attributed to the energy transfer from the ligands to the lanthanide ions, an antenna effect. Now, using these near-infrared luminescent lanthanide complexes, the luminescent spectral region from 800 to 1650 nm, can be covered completely, which is of particular interest for biomedical imaging applications, laser systems, and optical amplification applications. Copyright © 2015 John Wiley & Sons, Ltd.
Co-reporter:Miao Miao, Xin Feng, Gangling Wang, Shaomei Cao, Wen Shi, Liyi Shi
Particuology 2015 Volume 19() pp:53-59
Publication Date(Web):April 2015
DOI:10.1016/j.partic.2014.04.010
•Calcium sulfate hemihydrate (CSH) whiskers were prepared via phase transition of CSD.•Uniform and regular morphology CSH whiskers with high aspect ratio were obtained.•Impurities in FGD gypsum were found to have little effect on whisker growth.•The results suggested a possible application for FGD gypsum.Calcium sulfate hemihydrate (CSH) whiskers were synthesized by phase transition in CaCl2 solution under atmospheric pressure. Analytical-grade calcium sulfate dihydrate (AR CSD) was used as the raw material for the synthesis of CSH whiskers, according to orthogonal experiments. The effects of reaction temperature, AR CSD content, H2SO4 content, and reaction time were investigated, and the crystallization conditions were optimized. The as-prepared CSH whiskers displayed a regular morphology and a highly uniform size, with an aspect ratio of 105. A simulation system was also established by blending various sulfates with AR CSD, to evaluate the effects of impurities in flue gas desulfurization (FGD) gypsum. The main aim was to prepare CSH whiskers directly from FGD gypsum, without any purification, using the optimized conditions. This is a facile potential alternative process for large-scale production of CSH whiskers using abundant FGD gypsum as source materials.
Co-reporter:Qian Liu;Lifang Wei;Shuai Yuan;Xin Ren;Yin Zhao
Journal of Materials Science 2015 Volume 50( Issue 20) pp:6668-6676
Publication Date(Web):2015 October
DOI:10.1007/s10853-015-9221-8
The present work reports a simple Ni(CH3COO)2 post-treatment method, meanwhile represents a series of characterizations of bare and post-treated NiO photocathodes. The investigation enlightens the mechanisms responsible for NiO surface changes and its effects on the charge density, band-edge shifts, hole injection efficiency, interface recombination, transport, collection efficiency, and as the result influence on the photovoltaic devices’ performance. The primary results demonstrate that Ni(CH3COO)2 post-treatment can offer an effective way of decreasing surface NiO(OH) structure, resulting in diminishing the hole recombination, increasing the charge collection efficiency, and leading to 31.3 % increased photovoltaic performance.
Co-reporter:Xiaoqian Ge;Lining Sun;Song Dang;Jinliang Liu;Yanxia Xu;Zuwu Wei
Microchimica Acta 2015 Volume 182( Issue 9-10) pp:1653-1660
Publication Date(Web):2015 July
DOI:10.1007/s00604-015-1481-0
A new multifunctional nanocomposite is described that displays both upconversion and downconversion luminescence. It is based on upconversion nanoparticles (UCNPs) with a mesoporous coating that is boned with a terbium(III) complex. The modified mesoporous nanocomposite was characterized by transmission electron microscopy, X-ray powder diffraction, nitrogen adsorption-desorption isotherms, and photoluminescence spectra. They display dual (green and red) fluorescence under 980-nm excitation, and green fluorescence under 365-nm excitation. Both emissions can be easily detected by bare eyes. The material has low cytotoxicity and good biocompatibility as proven by the methyl thiazolyltetrazolium (MTT) assay. The nanocomposite was successfully applied to upconversion luminescence based in-vitro confocal imaging of the cytosol of murine macrophage cells (RAW264.7), and this resulted in images of excellent contrast. In addition, the particles display strongly temperature-dependent luminescence in the range from 280 K to 330 K.
Co-reporter:Lining Sun, Zuwu Wei, Haige Chen, Jinliang Liu, Jianjian Guo, Ming Cao, Tieqiao Wen and Liyi Shi
Nanoscale 2014 vol. 6(Issue 15) pp:8878-8883
Publication Date(Web):24 Jun 2014
DOI:10.1039/C4NR02312A
Folate receptors (FRs) are overexpressed on a variety of human cancer cells and tissues, including cancers of the breast, ovaries, endometrium, and brain. This over-expression of FRs can be used to target folate-linked imaging specifically to FR-expressing tumors. Fluorescence is emerging as a powerful new modality for molecular imaging in both the diagnosis and treatment of disease. Combining innovative molecular biology and chemistry, we prepared three kinds of folate-targeted up-conversion nanoparticles as imaging agents (UCNC-FA: UCNC-Er-FA, UCNC-Tm-FA, and UCNC-Er,Tm-FA). In vivo and in vitro toxicity studies showed that these nanoparticles have both good biocompatibility and low toxicity. Moreover, the up-conversion luminescence imaging indicated that they have good targeting to HeLa cells and can therefore serve as potential fluorescent contrast agents.
Co-reporter:Wei Yan, Wen-Juan Yu, Ling Wang, Dan Zhang, Xiao-Qian Ge, Jian-Zhong Hang, Wei Deng, Li-Yi Shi
Electrochimica Acta 2014 Volume 147() pp:257-264
Publication Date(Web):20 November 2014
DOI:10.1016/j.electacta.2014.09.120
Partially reduced graphene oxide nanosheet (prGON)/poly(sodium 4-styrenesulfonate) (PSS) composite with very high specific capacitance were prepared. Graphene oxide nanosheets (GON) were firstly partially reduced by a weak reducing agent, and PSS was attached to prGON through π–π stacking, acting as a spacer to prevent prGON from agglomeration. Otherwise, PSS could only bind GON through combining with the hydroxyl groups on GON. The prGON/PSS composite was then potentiostatically reduced at a constant potential. During the electrochemical reduction, the carbonyl groups on the prGON/PSS composite were gradually reduced to other oxygen functionalities instead of being removed. The redox-active oxygen-containing groups on the electrochemically reduced prGON/PSS composite were stable in the potential scanning range, and introduced pseudo-capacitance. The specific capacitance of the prGON/PSS composite after electrochemical reduction reached 367.2 F/g in 1 M KCl aqueous solution at the scanning rate of 5 mV/s, and retained its 93.8% capacitance after 1600 cycles. The superior capacitance performance can be ascribed to the outstanding intrinsic properties of graphene, the PSS spacer attached to prGON through π-π stacking, and the pseudo-capacitance introduced by the oxygen-containing groups.
Co-reporter:Peng Ding, Shuangshuang Su, Na Song, Shengfu Tang, Yimin Liu and Liyi Shi
RSC Advances 2014 vol. 4(Issue 36) pp:18782-18791
Publication Date(Web):23 Apr 2014
DOI:10.1039/C4RA00500G
The influence of the grafting-structures of different length polymer chains on the thermal conductive properties of polyamide-6/graphene (PG) nanocomposites are studied. The in situ thermal polycondensation method was used to realize length-controllable polyamide-6 (PA6) chains covalently grafted onto reduced graphene oxide (RGO) sheets, in which the content of graphene oxide was fixed and the thermal reduction of RGO was kept at a similar level. The experimental results show that the thermal conductivity (λ) of the PG nanocomposites decreases with the increasing length of the grafted PA6 chains (1.8 to 7.4 nm) from 0.293 to 0.265 W m−1 K−1. This result is in good agreement with previous simulation work and demonstrates that shorter PA6 chains are more effective in reducing the interface thermal resistance and improving the λ of the PG nanocomposites, which will promote research aimed at reducing the significant interface thermal resistance between the graphene and the polymer matrix to effectively improve the λ of thermal conductive materials.
Co-reporter:Lining Sun, Zhijuan Wang, Jin Z. Zhang, Jing Feng, Jinliang Liu, Yin Zhao and Liyi Shi
RSC Advances 2014 vol. 4(Issue 54) pp:28481-28489
Publication Date(Web):01 Jul 2014
DOI:10.1039/C4RA03781B
A new type of monodisperse mesoporous titania microspheres possessing visible (Eu3+, Sm3+) and near-infrared (Sm3+, Yb3+, Nd3+) luminescence were synthesized with covalent linking to Ln(dbm)3bpdc complexes (Ln = Eu, Sm, Yb, Nd, dbm = dibenzoylmethanate, bpdc = 2,2′-bipyridine-4,4′-dicarboxylic acid). These lanthanide complex-functionalized titania microspheres can be excited with visible light to extend the practical application in lighting devices and biomedical analysis. The materials were characterized using Fourier-transform infrared (FT-IR) spectroscopy, wide-angle X-ray powder diffraction (WAXD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), nitrogen adsorption/desorption, diffuse reflectance (DR) spectroscopy, fluorescence spectroscopy, and thermogravimetric analysis. The results show that the microsphere morphology composed of single anatase crystallites and mesoporous structure is retained after linking to the lanthanide complexes. To the best of our knowledge, this is the first successful attempt to graft lanthanide complexes onto mesoporous anatase titania microspheres with high crystallinity. The novel combination of lanthanide complexes with NIR luminescence under visible light excitation and mesoporous titania microspheres with high thermal and chemical stabilities as well as anatase crystallinity affords potential applications in the fields of energy conversion, photocatalysis, and biomaterials.
Co-reporter:Haiping Xu, Shuai Yuan, Zhuyi Wang, Yin Zhao, Jianhui Fang and Liyi Shi
RSC Advances 2014 vol. 4(Issue 17) pp:8472-8480
Publication Date(Web):15 Jan 2014
DOI:10.1039/C3RA47653G
A green and facile strategy was reported to synthesize the composite of graphene decorated with ZrO2 nanoparticles as a good candidate for the anode material of lithium-ion batteries. ZrO2 nanoparticles are uniformly anchored on the surface of graphene with an average size of 5.5 nm. This graphene/ZrO2 composite shows high specific capacity, high coulomb efficiency, excellent rate performance and cycling stability due to the sandwich-like stable structure with ZrO2 as the inert pillar supporting graphene, which offers more active sites for Li+ insertion. The strong interaction between graphene and ZrO2 plays a key role in maintaining the structure stability against the irreversible volume change during Li+ insertion/extraction.
Co-reporter:Haiping Xu, Jianhua Liao, Shuai Yuan, Yin Zhao, Meihong Zhang, Zhuyi Wang, Liyi Shi
Materials Research Bulletin 2014 51() pp: 326-331
Publication Date(Web):
DOI:10.1016/j.materresbull.2013.12.052
Co-reporter:Chongling Cheng, Hongjiang Liu, Xin Xue, Hui Cao, Liyi Shi
Electrochimica Acta 2014 120() pp: 226-230
Publication Date(Web):
DOI:10.1016/j.electacta.2013.12.049
Co-reporter:Zuwu Wei, Lining Sun, Jinliang Liu, Jin Z. Zhang, Huiran Yang, Yang Yang, Liyi Shi
Biomaterials 2014 35(1) pp: 387-392
Publication Date(Web):
DOI:10.1016/j.biomaterials.2013.09.110
Co-reporter:Lining Sun;Tao Liu;Yannan Qiu;Jinliang Liu;Liyi Shi
Microchimica Acta 2014 Volume 181( Issue 7-8) pp:775-781
Publication Date(Web):2014 June
DOI:10.1007/s00604-013-1073-9
We have developed a one-step method for the synthesis of mesoporous upconverting nanoparticles (MUCNs) of the type NaYF4:Yb,Er@mSiO2 in ammoniacal ethanol/water solution. The mesoporous silica is directly encapsulating the hydrophobic upconversion nanoparticles (UCNs) due to the presence of the template CTAB. Intense green emission (between 520 and 560 nm) and weaker red emission (between 630 and 670 nm) is observed upon 980-nm laser excitation. The MUCNs display low cytotoxicity (as revealed by an MTT test) and were successfully applied to label and image human nasopharyngeal epidermal carcinoma (KB) cells.
Co-reporter:Cheng Fang, Dengsong Zhang, Sixiang Cai, Lei Zhang, Lei Huang, Hongrui Li, Phornphimon Maitarad, Liyi Shi, Ruihua Gao and Jianping Zhang
Nanoscale 2013 vol. 5(Issue 19) pp:9199-9207
Publication Date(Web):16 Jul 2013
DOI:10.1039/C3NR02631K
Nanoflaky MnOx on carbon nanotubes (nf-MnOx@CNTs) was in situ synthesized by a facile chemical bath deposition route for low-temperature selective catalytic reduction (SCR) of NO with NH3. This catalyst was mainly characterized by the techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 adsorption–desorption analysis, X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR) and NH3 temperature-programmed desorption (NH3-TPD). The SEM, TEM, XRD results and N2 adsorption–desorption analysis indicated that the CNTs were surrounded by nanoflaky MnOx and the obtained catalyst exhibited a large surface area as well. Compared with the MnOx/CNT and MnOx/TiO2 catalysts prepared by an impregnation method, the nf-MnOx@CNTs presented better NH3-SCR activity at low temperature and a more extensive operating temperature window. The XPS results showed that a higher atomic concentration of Mn4+ and more chemisorbed oxygen species existed on the surface of CNTs for nf-MnOx@CNTs. The H2-TPR and NH3-TPD results demonstrated that the nf-MnOx@CNTs possessed stronger reducing ability, more acid sites and stronger acid strength than the other two catalysts. Based on the above mentioned favourable properties, the nf-MnOx@CNT catalyst has an excellent performance in the low-temperature SCR of NO to N2 with NH3. In addition, the nf-MnOx@CNT catalyst also presented favourable stability and H2O resistance.
Co-reporter:Dengsong Zhang, Lei Zhang, Liyi Shi, Cheng Fang, Hongrui Li, Ruihua Gao, Lei Huang and Jianping Zhang
Nanoscale 2013 vol. 5(Issue 3) pp:1127-1136
Publication Date(Web):04 Dec 2012
DOI:10.1039/C2NR33006G
The MnOx and CeOx were in situ supported on carbon nanotubes (CNTs) by a poly(sodium 4-styrenesulfonate) assisted reflux route for the low-temperature selective catalytic reduction (SCR) of NO with NH3. X-Ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR) and NH3 temperature-programmed desorption (NH3-TPD) have been used to elucidate the structure and surface properties of the obtained catalysts. It was found that the in situ prepared catalyst exhibited the highest activity and the most extensive operating-temperature window, compared to the catalysts prepared by impregnation or mechanically mixed methods. The XRD and TEM results indicated that the manganese oxide and cerium oxide species had a good dispersion on the CNT surface. The XPS results demonstrated that the higher atomic concentration of Mn existed on the surface of CNTs and the more chemisorbed oxygen species exist. The H2-TPR results suggested that there was a strong interaction between the manganese oxide and cerium oxide on the surface of CNTs. The NH3-TPD results demonstrated that the catalysts presented a larger acid amount and stronger acid strength. In addition, the obtained catalysts exhibited much higher SO2-tolerance and improved the water-resistance as compared to that prepared by impregnation or mechanically mixed methods.
Co-reporter:Hui Wang, Dengsong Zhang, Tingting Yan, Xiaoru Wen, Jianping Zhang, Liyi Shi and Qingdong Zhong
Journal of Materials Chemistry A 2013 vol. 1(Issue 38) pp:11778-11789
Publication Date(Web):25 Jul 2013
DOI:10.1039/C3TA11926B
In order to obtain excellent desalination behavior during the capacitive deionization (CDI) process, electrodes should provide efficient pathways for ion and electron transport. Here we open up a new opportunity to prepare high performance capacitive deionization (CDI) electrodes based on three-dimensional macroporous graphene architectures (3DMGA). The 3DMGA were fabricated by a simple template-directed method using polystyrene microspheres as sacrificial templates. The resulting 3DMGA exhibited a 3D interconnected structure with large specific surface area and high electric conductivity. The electrochemical behavior of the 3DMGA electrodes was analyzed by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. It was found that the 3DMGA showed superiority in electrosorption capacitance, low inner resistance, high reversibility and excellent stability. The power and energy density analysis further demonstrated that the 3DMGA electrode had a higher power output and lower energy consumption. According to the electrochemical measurements, the 3DMGA is quite desirable for high performance and low energy consumption capacitive deionization. The desalination capacity was evaluated by a batch mode electrosorptive experiment in a NaCl aqueous solution. An excellent desalination behavior of the 3DMGA was obtained due to the large accessible surface area, high electric conductivity and unique 3D interconnected macroporous structure. The 3DMGA was confirmed to be a promising material for CDI application.
Co-reporter:Lining Sun, Yannan Qiu, Tao Liu, Jin Z. Zhang, Song Dang, Jing Feng, Zhijuan Wang, Hongjie Zhang, and Liyi Shi
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 19) pp:9585
Publication Date(Web):September 24, 2013
DOI:10.1021/am402529w
A series of ternary lanthanide β-diketonate derivatives covalently bonded to xerogels (named as Ln-DP-xerogel, Ln = Sm, Yb, Nd, Er, Pr, Ho) by doubly functionalized alkoxysilane (dbm-Si) was synthesized in situ via a sol-gel process. The properties of these xerogel materials were investigated by Fourier-transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), diffuse reflectance (DR) spectroscopy, thermogravimetric analyses, and fluorescence spectroscopy. The data and analyses suggest that the lanthanide derivatives have been covalently grafted to the corresponding xerogels successfully. Of importance here is that, after excitation with visible light (400–410 nm), the xerogels all show characteristic visible (Sm3+) as well as near-infrared (NIR; Sm3+, Yb3+, Nd3+, Er3+, Pr3+, Ho3+) luminescence of the corresponding Ln3+ ions, which is attributed to the energy transfer from the ligands to the Ln3+ ions via an antenna effect. Exciting with visible light is advantageous over UV excitation. Furthermore, to the best of our knowledge, it is the first observation of NIR luminescence with visible light excitation from xerogels covalently bonded with the Sm3+, Pr3+, and Ho3+ derivatives. Compared to lanthanide complexes (Ln = Er, Nd, Yb) functionalized periodic mesoporous organosilica (PMO) materials that exhibit similar optical properties reported in our previous work, the Ln-DP-xerogel (Ln = Sm, Yb, Nd, Er, Pr, Ho) in this case offer advantages in terms of ease of synthesis and handling and potentially low cost for emerging technological applications. Development of near-infrared luminescence of the lanthanide materials with visible light excitation is of strong interest to emerging applications such as chemosensors, laser systems, and optical amplifiers.Keywords: covalently graft; lanthanide β-diketonate derivatives; NIR luminescent; visible-light excitation; xerogel;
Co-reporter:Xianjun Du, Dengsong Zhang, Ruihua Gao, Lei Huang, Liyi Shi and Jianping Zhang
Chemical Communications 2013 vol. 49(Issue 60) pp:6770-6772
Publication Date(Web):04 Jun 2013
DOI:10.1039/C3CC42418A
The modular catalysts were fabricated via the combination of the Ni–MgO–Al2O3 mixed oxide nanoplates and the mesoporous SiO2 coating. Due to the dual confinements, the catalysts show high catalytic activity with enhanced coke- and sintering-resistance in the dry reforming of methane reaction.
Co-reporter:Yanyan Lou, Shuai Yuan, Yin Zhao, Pengfei Hu, Zhuyi Wang, Meihong Zhang, Liyi Shi and Dongdong Li
Dalton Transactions 2013 vol. 42(Issue 15) pp:5330-5337
Publication Date(Web):17 Jan 2013
DOI:10.1039/C3DT32741H
A molecular surface chemical treatment is introduced into a dye sensitized solar cell (DSSC) incorporating metal nanoparticles to suppress the charge recombination. Dodecanethiol molecules as a surface treatment agent are successfully anchored onto the exposed Au nanoparticle sites of the ZnO nanorods/Au nanoparticles/N719 photoanode. ATR-FTIR and Raman measurements are conducted to understand the adsorptions of different molecules (dodecanethiol, N719) on the ZnO nanorods and Au nanoparticles surface. The effects of the dodecanethiol surface treatment on the performance of the plasmon-enhanced DSSC are investigated by UV-vis absorption, incident photon-to-current conversion efficiency (IPCE) and electrochemical impedance spectroscopy (EIS). The plasmon-enhanced light absorption due to the presence of Au nanoparticles is not affected by the dodecanethiol surface treatment. The charge recombination on the ZnO nanorods–dye–electrolyte interface is substantially retarded by insulating the exposed Au nanoparticle sites from the oxidized form of the electrolyte via dodecanethiol molecules. The strategy of a molecular surface chemical treatment on the photoanode of a DSSC with metal nanoparticles fully exploits the plasmon-enhanced light absorption and explores a simple method to protect the metal nanoparticles for the plasmon-enhanced DSSC.
Co-reporter:Ruili Liu, Shuai Yuan, Zhuyi Wang, Yin Zhao, Meihong Zhang and Liyi Shi
RSC Advances 2013 vol. 3(Issue 38) pp:17034-17038
Publication Date(Web):17 Jul 2013
DOI:10.1039/C3RA42326C
In order to reduce the interfacial thermal stress, a novel functionally graded YSZ/Al2O3 nanocoating (YSZ/Al2O3 FGC) which is hot corrosion resistant was developed with the sols of ZrO2, Y2O3 and AlOOH in this paper. SEM and XRD analyses indicated that the YSZ/Al2O3 FGC was about 4.2 μm in thickness and composed of t′-YSZ and γ-Al2O3 nanoparticles. Hot corrosion tests showed that the YSZ/Al2O3 FGC remarkably restrained the infiltration of the molten NaVO3 salt into the YSZ substrate. A thermal shock test at 700 °C showed that the thermal shock resistance of the YSZ/Al2O3 FGC was enhanced greatly compared with that of the Al2O3 coating. The improvement of the YSZ/Al2O3 FGC in the thermal cycle lifetime could be attributed to its compositionally graded structure, which decreased the thermal stress due to the thermal expansion coefficient mismatch between the YSZ substrate and the Al2O3 coating.
Co-reporter:Yi Lu, Zhuyi Wang, Shuai Yuan, Liyi Shi, Yin Zhao and Wei Deng
RSC Advances 2013 vol. 3(Issue 29) pp:11707-11714
Publication Date(Web):23 Apr 2013
DOI:10.1039/C3RA40670A
ZrO2 nanorods with different dispersibility were prepared via a facile microwave-hydrothermal approach in the absence of any organic modifier. XRD, TEM, HRTEM, N2 adsorption–desorption measurements (BET) and XPS were used to characterize the microstructure of as-prepared ZrO2 nanorods, and a possible mechanism was proposed to explain the formation and evolution of ZrO2 nanorods under microwave irradiation. The concentration of zirconium precursor was found to significantly affect the dispersion of ZrO2 nanorods, and the lower concentration of zirconium precursor favors the formation of ZrO2 nanorods with higher dispersibility under microwave irradiation. The as-prepared ZrO2 nanorods were further used to estimate their potential application as a humidity sensor. The sample with a higher concentration of surface oxygen vacancies exhibits a higher humidity sensor response due to more active sites for water adsorption, and the humidity sensing mechanism of ZrO2 nanorods was also discussed by complex impedance spectra in detail.
Co-reporter:Guojun Ding;Jifang Fu;Xing Dong;Liya Chen;Haisen Jia;Wenqi Yu;Liyi Shi
Polymer Composites 2013 Volume 34( Issue 10) pp:1753-1760
Publication Date(Web):
DOI:10.1002/pc.22579
Octaaminophenyl polyhedral oligomeric silsesquioxane (OAPS) was synthesized using three-step method and used to modify o-cresol-novolac epoxy resin (ECN) for printed circuit board. The influence of OAPS on the reactivity and the final properties of the hybrid networks were evaluated. The intercrosslinking reaction between ECN and OAPS was confirmed by Fourier transform infrared spectra. The ECN/OAPS hybrids have better impact strength, higher electrical resistivity and thermal stability, lower water absorption than the unmodified ECN. The volume resistivity and surface resistivity of the hybrids increase by an order of magnitude or more compared to the neat epoxy. The thermal stability of the hybrids improves by the incorporation of OAPS; the initial decomposition temperature and char yield show an increasing tendency up to 4 wt% loading of OAPS. The hybrids exhibit higher storage modulus and glass transition temperature (Tg) than the neat epoxy. The Tg of the hybrids greatly improves up to 153.3°C at 3 wt% content, much higher than 119.4°C of the neat epoxy. POLYM. COMPOS., 34:1753–1760, 2013. © 2013 Society of Plastics Engineers
Co-reporter:Dan Zhang ; Qi-Qi Dong ; Xiang Wang ; Wei Yan ; Wei Deng
The Journal of Physical Chemistry C 2013 Volume 117(Issue 40) pp:20446-20455
Publication Date(Web):September 16, 2013
DOI:10.1021/jp405850w
Three-dimensional ordered macroporous (3DOM) carbon nanotube (CNT)/polypyrrole (PPy) composite electrodes for supercapacitor application were prepared through cyclic voltammetric copolymerization from a solution containing both acid-treated CNTs and pyrrole monomers. A self-assembled SiO2 colloidal crystal was used as the sacrificial template. After electrochemical copolymerization, the template was removed, and a 3DOM CNT/PPy composite electrode was obtained. The specific capacitance of the composite reached 427 F g–1 at the scanning rate of 5 mV s–1, and it is calculated that ion diffusion contributed approximately 30% to the specific capacitance of the composite. A mathematical model of mass transport was proposed to evaluate the ion diffusion capability on the surfaces of 3DOM, nanoporous, and planar films. The calculation results showed that the flux (i.e., ion flux per unit length) of 3DOM film was larger than that of planar film, while the flux of nanoporous film was close to that of planar film. The model indicates that 3DOM film is favorable for ion transportation, while nanoporous film does the opposite. The model partially explains the reason why the specific capacitance of the prepared 3DOM CNT/PPy composite is far above the specific capacitance values of other reported CNT/PPy composites, even the nanoporous CNT/PPy composite.
Co-reporter:Phornphimon Maitarad, Dengsong Zhang, Ruihua Gao, Liyi Shi, Hongrui Li, Lei Huang, Thanyada Rungrotmongkol, and Jianping Zhang
The Journal of Physical Chemistry C 2013 Volume 117(Issue 19) pp:9999-10006
Publication Date(Web):April 18, 2013
DOI:10.1021/jp400504m
Manganese oxides (MnOx) supported on Ce0.9Zr0.1O2 (MnOx/Ce0.9Zr0.1O2) nanorods were synthesized and tested for low-temperature selective catalytic reduction of NO with ammonia. The catalysts were characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and hydrogen temperature-programmed reduction. The structure and morphology results show that the MnOx was highly dispersed on the surface of Ce0.9Zr0.1O2 nanorods. Various species, such as Mn2+, Mn3+, and Mn4+, were exposed due to a strong interaction between manganese and cerium oxides. Thus, the MnOx/Ce0.9Zr0.1O2 nanorods exhibited a better catalytic performance (90% NO conversion at 150 °C) compared with that of the as-prepared Ce0.9Zr0.1O2 nanorods. Density functional theory (DFT) calculations clearly demonstrated that the MnOx on the surface of supporting nanorods or Mn@CeO2(110) could easily form an oxygen vacancy distortion. Furthermore, the Mn@CeO2(110) model in the DFT analysis showed a prominent effect on the NO and NH3 adsorption which resulted in a stronger nitrite intermediate (NOO*) formation and more attractive interaction with the NH3 gas compared with those observed with the CeO2(110) model. Therefore, a thorough understanding of the structure and catalytic performance of MnOx/Ce0.9Zr0.1O2 nanorods was successfully achieved by a combination of experimental and theoretical studies.
Co-reporter:Dan Shang;Xiaoying Sun;Jianzhong Hang
Journal of Sol-Gel Science and Technology 2013 Volume 67( Issue 1) pp:39-49
Publication Date(Web):2013 July
DOI:10.1007/s10971-013-3048-z
A series of silica sols modified by γ-methacryloxypropyltrimethoxysilane (MPS) were synthesized by the acid-catalyzed sol–gel method, and then the solvent in these sols were extracted under several vacuum distillation conditions. The stability of the sol after the distillation can be improved by means of increasing the dosage of MPS and incorporating reactive diluent TPGDA into the sol as new dispersion medium. Optimized samples have maintained stable for over 180 days. The sol dispersions and UV-curable organic compounds were mixed to form the hybrid coatings for fire protection. Effects of the distillation treatment and the cosolvent anhydrous ethanol added into the reaction solution on thermal and combustion performances and physical properties of the hybrid coatings were studied by thermogravimetric analysis, microscale combustion calorimeter, limit oxygen index test and UL-94 horizontal test, etc. The results showed that the distillation treatment for the sol was necessary to improve thermal performance and physical properties of the hybrid coatings. In addition, in the flammability experiment, hybrid coatings showed a quick and efficient protection of the substrate.
Co-reporter:Yan-Yan Lou;Shuai Yuan;Yin Zhao;Zhu-Yi Wang
Advances in Manufacturing 2013 Volume 1( Issue 4) pp:340-345
Publication Date(Web):2013 December
DOI:10.1007/s40436-013-0046-x
The relationship between bilayer nanostructure, defect density and dye-sensitized solar cell (DSCC) performances was investigated. By adjusting bilayer nanostructures, defect density of ZnO nanodendrite-nanorods structure was decreased comparing to that of nanoflower-nanorods structure. The performances of DSCC based on ZnO nanodendrites-nanorods structure and nanoflower-nanorods structure were studied by Raman spectrum, room temperature photoluminescence, dye loading, photocurrent density-voltage characteristic and open-circuit voltage decay (OCVD) technique. The device with nanodendrite-nanorods structure has lower charge recombination rate and prolonged electron lifetime due to its microstructure feature.
Co-reporter:Shuai Yuan, Hui Huang, Zhuyi Wang, Yin Zhao, Liyi Shi, Chuanbing Cai, Dongdong Li
Journal of Photochemistry and Photobiology A: Chemistry 2013 Volume 259() pp:10-16
Publication Date(Web):1 May 2013
DOI:10.1016/j.jphotochem.2013.02.020
Composite photoelectrodes consisting of mesoporous TiO2 and three-dimensional (3D) fluorine-doped tin oxide (FTO) conductive grid were fabricated. The nanostructures of prepared photoelectrodes were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The power conversion performances of DSCs based on composite photoelectrodes were investigated by the current density–voltage (J–V) characteristics. Compared to TiO2 based DSCs, DSCs based on FTO conductive grid exhibit higher short-circuit current density (Jsc) and power conversion efficiency (PCE). The analysis on electrochemical impedance spectroscopy (EIS) reveals that the higher photoelectric conversion performance of DSCs with FTO conductive grid is attributed to more competitive electron collection than recombination.Graphical abstractHighlights► DSC photoelectrode based on three dimensional FTO conductive grid was fabricated. ► FTO conductive grid can shorten electron transport distance. ► FTO conductive grid can increase photocurrent density and power conversion efficiency of DSC.
Co-reporter:Dengsong Zhang, Tingting Yan, Liyi Shi, Zheng Peng, Xiaoru Wen and Jianping Zhang
Journal of Materials Chemistry A 2012 vol. 22(Issue 29) pp:14696-14704
Publication Date(Web):2012/05/24
DOI:10.1039/C2JM31393F
Graphene/carbon nanotube (GR/CNT) composites were prepared by a modified exfoliation approach and used as capacitive deionization (CDI) electrodes. SEM and TEM images demonstrate that the CNTs are successfully inserted into the GR. Nitrogen sorption analysis and electrochemical impedance spectroscopy show that the GR/CNT composites have a larger specific surface area and higher conductivity as compared with GR, which is due to the inserted CNTs inhibiting the aggregation and increasing the conductivity in the vertical direction. Through cyclic voltammetry and galvanostatic charge/discharge evaluation, we can conclude that the prepared composites have higher specific capacitance values and better stability, suggesting that the GR/CNT composite electrodes have a higher electrosorption capacity. Power and energy density analysis shows that the GR/CNT composite electrodes have higher power density and energy density and the energy density decay is relatively slow in a wide range of power as compared with GR, which indicates that the composite electrodes exhibit low energy consumption for capacitive deionization. The desalination capacity was evaluated by a batch mode electrosorptive experiment in a NaCl aqueous solution. As compared with GR and commercial activated carbon, the GR/CNT composite electrodes exhibit excellent desalination behavior, which is attributed to the improved electric conductivity and higher accessible surface area, which are quite beneficial for the electrosorption of ions onto the electrodes. The GR/CNT composites are confirmed to be promising materials for CDI electrodes.
Co-reporter:Guozhang Zhao;Liyi Shi;Jifang Fu;Xin Feng;Peng Ding;Jing Zhuo
Journal of Applied Polymer Science 2012 Volume 123( Issue 6) pp:3734-3740
Publication Date(Web):
DOI:10.1002/app.34406
Abstract
Ethylene–propylene–diene monomer/polytetrafluorethylene (EPDM/PTFE) composites based on EPDM and electron beam irradiated PTFE powders (MS-II, MS-III, and MS-V, with mean diameter 5 μm, 1 μm, and 0.1 μm, respectively) were prepared by a mechanical compounding technique. The curing characteristics, morphologies, mechanical properties, and abrasion behaviors of these composites were investigated. The curing measurements indicated that the addition of lower loading of MS-III or MS-V enhanced the lubrication of EPDM compounds and delayed the curing process. The morphological structure of the composites demonstrated that the MS-III and MS-V were uniformly dispersed in EPDM matrix and the efficient polymer–filler interfacial interactions were constructed. In comparison with EPDM/MS-II and EPDM/MS-III, EPDM/MS-V exhibited outstanding tensile strength, tear strength, elongation at break, and abrasion resistance due to the nanometer particle dimension and good dispersion of MS-V as well as the stronger interfacial interactions between MS-V and the EPDM matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Co-reporter:Fan Xu;Xiaoying Sun;Jianzhong Hang
Journal of Sol-Gel Science and Technology 2012 Volume 63( Issue 3) pp:382-388
Publication Date(Web):2012 September
DOI:10.1007/s10971-012-2797-4
A ternary sol containing silicon, phosphorus and boron modified by γ-methacryloxypropyltrimethoxysilane was synthesized by sol–gel method. The ternary sol was incorporated into the organic matrix and UV-curable organic/inorganic hybrid coating materials were obtained. Hardness, transmittance, haze, cross-cut adhesion and abrasion resistance results showed that the mechanical properties of the hybrid coatings improved effectively with no comprising on optical properties by increasing sol content. Scanning electron microscopy and Energy Dispersive X-ray spectrometer studies indicated that inorganic particles were homogenously dispersed in the organic matrix. The flame retardancy of the UV-curable coatings was investigated by thermogravimetric analysis and microscale combustion calorimeter. The results showed that the incorporation of sol into the organic network led to an improvement in the thermal stability and flame retardancy of the hybrid coating materials. It is a desirable achievement to improve simultaneously both flame retardancy and mechanical properties of the coatings.
Co-reporter:Weiwei Li;Yin Zhao;Shuai Yuan;Liyi Shi;Zhuyi Wang
Journal of Materials Science 2012 Volume 47( Issue 23) pp:7999-8006
Publication Date(Web):2012 December
DOI:10.1007/s10853-012-6689-3
Anatase TiO2 nanocrystal colloids with high dispersion and photocatalytic activity were rapidly synthesized from peroxo-titanium-acid precursor by microwave-assisted hydrothermal method within 30 min at low temperature (120–180 °C). The transmission electron microscopy results indicate that the as-prepared TiO2 have a narrow particle size distribution (25–29 nm) and high dispersion. The crystal structure of all these products are pure anatase phase (XRD, Raman), and they show good crystallinity and large surface area (N2 adsorption–desorption measurements BET). The results of the UV–Visible absorbance and Fourier transform infrared spectra indicate that the surface peroxo group Ti(O2) still remains in TiO2 nanoparticles prepared by microwave-assisted hydrothermal method at 120 °C, and this surface peroxo group can be decomposed effectively by drying at 140 °C. The photocatalytic activity of the as-prepared TiO2 were evaluated by the degradation of reactive brilliant red X-3B, it is found that the as-prepared TiO2 exhibited good photocatalytic performance. Moreover, the existence of surface peroxo group greatly suppressed the photocatalytic activity of the TiO2 nanoparticles.
Co-reporter:Zheng Liu, Lining Sun, Fuyou Li, Qian Liu, Liyi Shi, Dengsong Zhang, Shuai Yuan, Tao Liu and Yannan Qiu
Journal of Materials Chemistry A 2011 vol. 21(Issue 44) pp:17615-17618
Publication Date(Web):18 Oct 2011
DOI:10.1039/C1JM13871E
A simple and versatile method was proposed for self-assembling magnetic nanoparticles and hydrophobic upconversion nanoparticles on to a mesoporous nanoprobe by the means of an electrostatic interaction and binding scheme. The hybrid nanoprobes showed good magnetic and near-infrared luminescent properties, and could be explored as biosensors.
Co-reporter:Jia Liu, Yin Zhao, Liyi Shi, Shuai Yuan, Jianhui Fang, Zhuyi Wang, and Meihong Zhang
ACS Applied Materials & Interfaces 2011 Volume 3(Issue 4) pp:1261
Publication Date(Web):February 28, 2011
DOI:10.1021/am2000642
The Sn4+-doped TiO2 nanocrystals with controlled crystalline phase and morphology had been successfully prepared through easily adjusting the solvent system from the peroxo-metal-complex precursor by solvothermal method. The Sn4+-doped TiO2 nanocrystals were characterized by XRD, Raman, TEM, HRTEM, XPS, ICP-AES, BET, and UV−vis. The experimental results indicated that the Sn4+-doped TiO2 nanocrystals prepared in the pure water or predominant water system trend to form rodlike rutile, whereas the cubic-shaped anatase Sn4+-doped TiO2 nanocrystals can be obtained in the alcohol system. The growth mechanism and microstructure evolution of the Sn4+-doped TiO2 nanocrystals prepared in the different solvent systems are discussed. The liquid-phase photocatalytic degradation of phenol was used as a model reaction to test the photocatalytic activity of the synthesized materials. It was found that sample Sn4+-doped TiO2 prepared in 1-butanol showed the maximum photoactivity, which attributed to higher band gap, optimal crystalline phase and surface state modifications.Keywords: crystalline phase; morphology; photocatalytic activity; solvothermal; TiO2
Co-reporter:Dengsong Zhang, Fuhuan Niu, Tingting Yan, Liyi Shi, Xianjun Du, Jianhui Fang
Applied Surface Science 2011 Volume 257(Issue 23) pp:10161-10167
Publication Date(Web):15 September 2011
DOI:10.1016/j.apsusc.2011.07.010
Abstract
The ceria nanospindles have been successfully synthesized via a simple template-free solvothermal treatment by employing a mixture of glycerin and water as the reaction solvent. The properties of the ceria nanospindles were characterized. A series of control experiments confirms that the reaction solvents, reaction temperature and time are the crucial factors determining the formation of ceria nanospindles, and by adjusting the experimental parameters the other ceria micro/nanostructures such as columns, spheres, and rods were obtained. The platinum coated ceria nanospindles show the excellent low-temperature catalytic activity in the oxidation of carbon monoxide as compared with other micro/nanostructures, which is mainly due to their special shape and uniformly-distributed active sites.
Co-reporter:Tingting Yang, Xin Feng, Qingli Tang, Wenwen Yang, Jianhui Fang, Gangling Wang, Wen Shi, Liyi Shi, Peng Ding
Journal of Alloys and Compounds 2011 Volume 509(Issue 24) pp:L236-L238
Publication Date(Web):16 June 2011
DOI:10.1016/j.jallcom.2011.03.185
MoS2 nanolamellers were synthesized by a one-step oxidation–reduction reaction in solution, in which the (NH4)2MoS4 and H2C2O4·2H2O were used as reactants and then calcined at 800 °C under N2 for 1 h. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The diameter and nanoplate thickness of the obtained MoS2 nanolamellers were approximately 80 nm and 20–30 nm, respectively. These novel structures of nanolamellers had potential applications in solid lubricants.
Co-reporter:Dengsong Zhang, Tingting Yan, Hongrui Li, Liyi Shi
Microporous and Mesoporous Materials 2011 Volume 141(1–3) pp:110-118
Publication Date(Web):May 2011
DOI:10.1016/j.micromeso.2010.10.045
A simple solution route was introduced for the fabrication of uniform mesoporous EuF3 nanospheres by using Eu(NO3)3 and ionic liquids ([BMIM]BF4) as the starting reaction reagents at room temperature under ambient pressure without any surfactants and templates. The mesoporous samples were characterized by X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, as well as N2 adsorption–desorption. The mesoporous EuF3 nanospheres are composed of tiny nanocrystals with a size of ca. 5 nm. The time dependent studies of the reactions have been conducted to reveal the morphological evolution of mesoporous EuF3 nanospheres. An intensive emission peak at around 592 nm was observed at room temperature for the mesoporous EuF3 nanospheres due to the 5D0–7F1 magnetic-dipole transition of Eu3+ ions.Graphical abstractResearch highlights► Mesoporous EuF3 nanospheres were prepared by using ionic liquids as the fluoride source at room temperature under ambient pressure. ► Ionic liquids act not only as a fluoride supplier but also as a morphology directing agent. ► An intensive emission peak at around 592 nm was observed at room temperature for the mesoporous EuF3 nanospheres.
Co-reporter:Dengsong Zhang, Fuhuan Niu, Hongrui Li, Liyi Shi, Jianhui Fang
Powder Technology 2011 Volume 207(1–3) pp:35-41
Publication Date(Web):15 February 2011
DOI:10.1016/j.powtec.2010.10.007
The size-controlled ceria nanospheres have successfully synthesized via a simple solvothermal treatment by employing the mixtures of water and diethylene glycol as the reaction solvent with the aid of polyvinylpyrrolidone. The properties of the ceria nanospheres were characterized. The synthesis parameters were investigated in detail by a series of control experiments. It is found that the surfactant species and reaction solvents were the crucial factors determining the formation of ceria nanospheres, and the size of ceria nanospheres can be controlled by adjusting the reaction temperature and time. The noble metal coated ceria nanospheres shows the excellent catalytic activity in the conversion of carbon monoxide, and especially for Au coated ceria nanospheres, the T50, where 50% CO was converted to CO2, can reach to 62.0 °C.The size-controlled ceria nanospheres were synthesized via a simple solvothermal treatment with the aid of polyvinylpyrrolidone and the Au@ceria nanospheres shows the excellent catalytic activity in the CO oxidation.
Co-reporter:Xiaoqiang He, Dengsong Zhang, Hongrui Li, Jianhui Fang, Liyi Shi
Particuology 2011 Volume 9(Issue 1) pp:80-85
Publication Date(Web):February 2011
DOI:10.1016/j.partic.2010.07.006
Ceria nanoparticles with various shapes (rods, cubes, and plates) and sizes were controllably synthesized and then introduced into epoxy resin. Subsequently, we investigated correlations between the shape and size of ceria nanostructures and the mechanical performance of composites. The samples were characterized by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. Compared with commercial ceria filled composites, the composites made with morphology-controlled ceria nanostructures show a higher impact strength. It is found that epoxy resins made with high-aspect-ratio ceria nanorods show the highest impact strength, up to 17.27 kJ/m2, which is about four times that of the neat epoxy resin.Compared with commercial ceria filled epoxy composites, those made with morphology-controlled ceria nanostructures show higher impact strength, and epoxy resins made with high-aspect-ratio ceria nanorods show the highest impact strength, up to 17.27 kJ/m2, about four times that of the neat epoxy resin.
Co-reporter:Zheng Peng ; Dengsong Zhang ; Liyi Shi ; Tingting Yan ; Shuai Yuan ; Hongrui Li ; Ruihua Gao ;Jianhui Fang
The Journal of Physical Chemistry C 2011 Volume 115(Issue 34) pp:17068-17076
Publication Date(Web):August 4, 2011
DOI:10.1021/jp2047618
Mesoporous carbons with various porous structures, such as 2-D hexagonal (P6m), 3-D cubic symmetry (Im3̅m), and 3-D bicontinuous (Ia3̅d) space groups, were used to prepare electrodes in desalinating capacitors which were used to remove ions from the saltwater solution. The parallel analysis was conducted with nitrogen adsorption–desorption, small-angle X-ray diffraction, transmission electron microscopy, and so on. The influence of pore structure and size of mesoporous carbon electrodes and ion types on the electroadsorption processes were investigated. The hydrophilic characteristics of the carbon electrodes surface were compared by water contact angle. It is demonstrated that electroadsorption characteristics of mesoporous carbon electrodes vary for the different mesopores and different types of ions. The relationship between the electrochemical capacitive ability and ion dimensions was established. These mesoporous carbons have been proved to be promising electrode materials with good reversibility and high stability, which can be potentially used for capacitive deionization.
Co-reporter:Shanshan Wu, Shuai Yuan, Liyi Shi, Yin Zhao, Jianhui Fang
Journal of Colloid and Interface Science 2010 Volume 346(Issue 1) pp:12-16
Publication Date(Web):1 June 2010
DOI:10.1016/j.jcis.2010.02.031
Fluorine-doped tin dioxide (FTO) nanocrystals were prepared with a sol–gel process followed by a hydrothermal treatment using SnCl4 and NH4F as SnO2 and fluorine dopant, respectively. The nanostructure and composition were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), zeta potential analysis, electrochemical measurement technology and X-ray photoelectron spectroscopy (XPS) respectively. The diameter of the fluorine doped SnO2 nanocrystal in rutile-type structure is about 10 nm. Compared to the pure SnO2 nanocrystals, the fluorine doped SnO2 nanocrystals can be dispersed homogeneously in H2O, forming transparent sol with high stability. The powder of fluorine doped SnO2 nanocrystals could be obtained by removing the solvent, and the electrical resistivity properties were measured by a four-point probe measurement. The results show that sheet resistances (Rs) of fluorine doped SnO2 decrease with the increasing NH4F/Sn molar ratio in the range from 0 to 2. However, further increase of NH4F/Sn molar ratio from 2 to 5 leads to higher sheet resistance. The F/Sn molar ratio of fluorine doped SnO2 measured by XPS is about 0.18 when NH4F/Sn molar ratio is equal to 2, and the sheet resistance of fluorine doped SnO2 powder is 110Ω/□.The HRTEM image and FFT pattern reveal that the fluorine doped SnO2 nanocrystals are of cassiterite structure.
Co-reporter:Dengsong Zhang, Tingting Yan, Liyi Shi, Hongrui Li, Joseph F. Chiang
Journal of Alloys and Compounds 2010 Volume 506(Issue 1) pp:446-455
Publication Date(Web):10 September 2010
DOI:10.1016/j.jallcom.2010.07.026
A simple aqueous solution route was introduced for the fabrication of uniform Eu(OH)3 and Eu2O3 nanospindles, nanorods and nanobundles by using Eu(NO3)3 and NaOH as the starting reaction reagents at room temperature and atmosphere pressure without any surfactant and template. The influence of the molar ratios of [OH−]/[Eu3+], reaction time, and temperature was investigated. It is demonstrated that the size of Eu(OH)3 nanospindle can be well tuned by adjusting the [Eu3+]/[OH−] molar ratios. The possible growth mechanism of Eu(OH)3 and Eu2O3 nanostructures is also discussed. The room-temperature photoluminescence analysis shows that Eu2O3 nanostructures have an intensive emission peak of Eu3+ ion at around 611 nm due to the 5D0–7F2 forced electric dipole transition of Eu3+ ions. It is found that the relative peak intensity increases with increasing reaction time.Research highlightsIt is still very significant to develop a simple approach for large-scale synthesis of Eu(OH)3 and Eu2O3 nanostructured without the assistance of any added surfactant, catalyst or template under an ambient temperature. In this paper, a simple aqueous solution route was introduced for the fabrication of uniform Eu(OH)3 and Eu2O3 nanospindles, nanorods and nanobundles by using Eu(NO3)3 and NaOH as the starting reaction reagents at room temperature and atmosphere pressure without any surfactant and template. The influence of the molar ratios of [OH−]/[Eu3+], reaction time, and temperature was investigated. It is demonstrated that the size of Eu(OH)3 nanospindle can be well tuned by adjusting the [Eu3+]/[OH−] molar ratios. The possible growth mechanism of Eu(OH)3 and Eu2O3 nanostructures is also discussed. The room-temperature photoluminescence analysis shows that Eu2O3 nanostructures have an intensive emission peak of Eu3+ ion at around 611 nm due to the 5D0–7F2 forced electric dipole transition of Eu3+ ions. It is found that the relative peak intensity increases with increasing reaction time.
Co-reporter:Dengsong Zhang, Hailing Mai, Lei Huang, Liyi Shi
Applied Surface Science 2010 Volume 256(Issue 22) pp:6795-6800
Publication Date(Web):1 September 2010
DOI:10.1016/j.apsusc.2010.04.091
Abstract
Carbon nanotubes (CNTs) were controllably coated with the uninterrupted CuO and CeO2 composite nanoparticles by a facile pyridine-thermal method and the high catalytic performance for CO oxidation was also found. The obtained nanocomposites were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction as well as X-ray photoelectron spectroscopy. It is found that the CuO/CeO2 composite nanoparticles are distributed uniformly on the surface of CNTs and the shell of CeO2/CuO/CNT nanocomposites is made of nanoparticles with a diameter of 30–60 nm. The possible formation mechanism is suggest as follows: the surface of CNTs is modified by the pyridine due to the π–π conjugate role so that the alkaline of pyridine attached on the CNT surface is more enhanced as compared to the one in the bulk solvent, and thus, these pyridines accept the proton from the water molecular preferentially, which result in the formation of the OH− ions around the surface of CNTs. Subsequently, the metal ions such as Ce3+ and Cu2+ in situ react with the OH− ions and the resultant nanoparticles deposit on the surface of CNTs, and finally the CeO2/CuO/CNT nanocomposites are obtained. The T50 depicting the catalytic activity for CO oxidation over CeO2/CuO/CNT nanocomposites can reach ∼113 °C, which is much lower than that of CeO2/CNT or CuO/CNT nanocomposites or CNTs.
Co-reporter:Le Yu, Shuai Yuan, Liyi Shi, Yin Zhao, Jianhui Fang
Microporous and Mesoporous Materials 2010 Volume 134(1–3) pp:108-114
Publication Date(Web):October 2010
DOI:10.1016/j.micromeso.2010.05.015
A simple method to prepare Cu2+ doped mesoporous TiO2 with improved visible sensitive photocatalytic activity is reported. The mesoporous samples were characterized by low angle and wide angle X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption–desorption, X-ray photoelectron spectra (XPS) and UV–visible absorbance spectroscopy. The degradation of methylene blue under visible light irradiation was investigated to evaluate the photocatalytic activity of these materials. Analytical results demonstrate that Cu2+ doping amount is crucial to affect the photocatalytic ability of the mesoporous titania. Among the samples, 0.05 at.% Cu2+ doped mesoporous TiO2 exhibits the highest photocatalytic activity.
Co-reporter:Chunhua Ge;Liyi Shi;Hui Yang;Shengfu Tang
Polymer Composites 2010 Volume 31( Issue 9) pp:1504-1514
Publication Date(Web):
DOI:10.1002/pc.20937
Abstract
Poly(ethylene terephthalate) (PET)/Barite nanocomposites were prepared by direct melt compounding. The nonisothermal melt crystallization kinetics of pure PET and PET/Barite nanocomposites, containing unmodified Barite and surface-modified Barite (SABarite), was investigated by differential scanning calorimetry (DSC) under different cooling rates. With the addition of barite nanoparticles, the crystallization peak became wider and shifted to higher temperature and the crystallization rate increased. Several analysis methods were used to describe the nonisothermal crystallization behavior of pure PET and its nanocomposites. The Jeziorny modification of the Avrami analysis was only valid for describing the early stage of crystallization but was not able to describe the later stage of PET crystallization. Also, the Ozawa method failed to describe the nonisothermal crystallization behavior of PET. A combined Avrami and Ozawa equation, developed by Liu, was used to more accurately model the nonisothermal crystallization kinetics of PET. The crystallization activation energies calculated by Kissinger, Takhor, and Augis-Bennett models were comparable. The results reveal that the different interfacial interactions between matrix and nanoparticles are responsible for the disparate effect on the crystallization ability of PET. POLYM. COMPOS., 31:1504–1514, 2010. © 2009 Society of Plastics Engineers
Co-reporter:Weiwei Yan, Liyi Shi, Shuai Yuan, Yin Zhao, Jianhui Fang, Jian Zhao
Materials Letters 2010 Volume 64(Issue 10) pp:1208-1210
Publication Date(Web):31 May 2010
DOI:10.1016/j.matlet.2010.02.052
Nanoporous silica colloids were prepared by a convenient single-step sol–gel process. In this approach, acidic aluminum nitrate (Al(NO3)3) solution was added to the ethanol solution of tetraethoxy orthosilicate (TEOS). In the preliminary stage, alumina/silica core-shell particles were formed. Then the Al2O3 cores were dissolved subsequently with the decrease of pH value, and the nanoporous silica was formed. The porous silica particles were characterized by transmission electron microscopy (TEM). The formation mechanism of the porous silica was discussed.
Co-reporter:Dengsong Zhang, Chengsi Pan, Liyi Shi, Lei Huang, Jianhui Fang, Hongxia Fu
Microporous and Mesoporous Materials 2009 Volume 117(1–2) pp:193-200
Publication Date(Web):1 January 2009
DOI:10.1016/j.micromeso.2008.06.022
In this work, the nanocomposites, carbon nanotubes (CNTs) coated with nanosized ceria, were prepared by a facile solvothermal method. The obtained nanocomposites have a dense overlayer which is made of nanoparticles with the diameter of ∼10 nm. Ceria nanotubes with a porous and hollow structure were fabricated by the removal of CNTs, which possess high surface area and remarkable thermal stability. The products were characterized by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The parameters affecting the formation of CeO2 nanotubes were discussed in details. The key steps involved in the formation of the CeO2 nanotubes are solvothermal modifications of CNTs and controlled calcinations. CeO2 nanotubes have an excellent catalytic performance for the CO oxidation. The remains of the templates in the CeO2 nanotubes are considered to play an important part in the enhanced catalytic activity for the formation of CeO2−xCx.
Co-reporter:Jianzhong Hang, Liyi Shi, Xin Feng, Lin Xiao
Powder Technology 2009 Volume 192(Issue 2) pp:166-170
Publication Date(Web):5 June 2009
DOI:10.1016/j.powtec.2008.12.010
Electrostatic and electrosteric stabilization of aqueous suspensions of barite nanoparticles were investigated. The state of dispersion was evaluated in terms of zeta potential, apparent viscosity and the mean particle size of solid phase in the solution. Zeta potential, apparent viscosity and the mean particle size as a function of pH were performed in absence of dispersant. The result showed that electrostatic stabilization of the aqueous suspension of barite nanoparticles can be accomplished in low acidic and high basic range of pH. In presence of sodium polyacrylate (PAA-Na) dispersant, the isoelectric point (IEP) of the barite nanoparticles was shifted to lower pH and the negative zeta potential was increased in a large range of pH above the (IEP). The optimum amount of PAA-Na dispersant is discussed in the light of zeta potential and viscosity. It is found that the adsorption of PAA is correlated to the net surface charge of the barite nanoparticles and the fraction of dissociated polymer at pH 4, 8.5 and 10. At pH 4, the state of dispersion was achieved at higher amount of electrolyte due to the low fraction of negatively charged dissociated polymer and the positively charge particles. At basic pH, the fraction of dissociated polymer was high and the surface charge of particle was highly negative, therefore, the lowest viscosity was obtained at a small amount of PAA. In addition, the optimum amount of polymer decreased with the increase in pH of the suspension.Graphical abstractAt basic pH, the fraction of dissociated sodium polyacrylate was high and the surface charge of particle was highly negative, therefore, the lowest viscosity was obtained at a small amount of PAA.
Co-reporter:Tingting Yan, Dengsong Zhang, Liyi Shi, Hongrui Li
Journal of Alloys and Compounds 2009 Volume 487(1–2) pp:483-488
Publication Date(Web):13 November 2009
DOI:10.1016/j.jallcom.2009.07.165
A large-scale synthesis of uniform Eu2O3 nanorods was realized without templates by a simple precipitation method under ambient pressure with the subsequent calcination. The products were characterized by X-ray diffraction spectroscopy, transmission electron microscopy, scanning electron microscopy, thermogravimetry and differential scanning calorimetry. It is demonstrated that the Eu2O3 nanorods with the pure body-centered cubic structure have a diameter of ∼20 nm and a length of 100–300 nm. The influence of reaction temperature, solution concentration, and reaction time on the formation of nanorods is investigated, and the possible growth mechanism is also discussed. The room temperature photoluminescence analysis shows that Eu2O3 nanorods have a strong red emission peak of Eu3+ ion at around 611 nm due to the 5D0 → 7F2 forced electric dipole transition of Eu3+ ions.
Co-reporter:Tingting Yan, Dengsong Zhang, Liyi Shi, Haopeng Yang, Hailing Mai, Jianhui Fang
Materials Chemistry and Physics 2009 Volume 117(Issue 1) pp:234-243
Publication Date(Web):15 September 2009
DOI:10.1016/j.matchemphys.2009.05.047
Monodisperse Y2O3:Eu3+ nanospheres have been successfully synthesized by a low-temperature reflux method assisted by cetyltrimethyl ammonium bromide (CTAB). The products were characterized by X-ray diffraction spectroscopy, transmission electron microscopy, scanning electron microscopy, Fourier-transform infrared spectrophotometer, thermogravimetric and differential thermal analysis, and X-ray photoelectron spectroscopy. It is demonstrated that the size of Y2O3:Eu3+ nanospheres can be controlled from 80 to 140 nm with narrow size distribution by adjusting the amount of CTAB. A possible formation mechanism of Y2O3:Eu3+ nanospheres has been proposed. The photoluminescence analysis shows that Y2O3:Eu3+ nanospheres obtained have a strong red emission peak of Eu3+ ions at around 611 nm, due to the 5D0 → 7F2 forced electric dipole transition of Eu3+ ions. It is found that the photoluminescence performance of the obtained Y2O3:Eu3+ nanospheres is stronger than that of the Y2O3:Eu3+ nanorods synthesized by a traditional hydrothermal route.
Co-reporter:Fuhuan Niu, Dengsong Zhang, Liyi Shi, Xiaoqiang He, Hongrui Li, Hailing Mai, Tingting Yan
Materials Letters 2009 Volume 63(24–25) pp:2132-2135
Publication Date(Web):15 October 2009
DOI:10.1016/j.matlet.2009.07.021
Au/CeO2 nanorods of ~ 15 nm in diameter and 100–400 nm in length have been synthesized through an efficient and simple method, and subsequently the novel low-temperature catalytic performance of Au/CeO2 nanorods for CO oxidation is found. The composites are characterized by transmission electron microscopy, X-ray diffraction as well as X-ray photoelectron spectroscopy. It is found that the Au nanoparticles with an average diameter of 8 nm are distributed uniformly on the surface of CeO2 nanorods. The possible formation mechanism of Au/CeO2 nanorods has been discussed. The T50 depicting the catalytic activity for CO oxidation can reach 62.1 °C, which is much lower than that of CeO2 nanorods or Au/CeO2 powders. In addition, Au/CeO2 nanorods exhibit excellent stability as catalysts for CO oxidation.
Co-reporter:Jianhua Liao, Liyi Shi, Shuai Yuan, Yin Zhao and Jianhui Fang
The Journal of Physical Chemistry C 2009 Volume 113(Issue 43) pp:18778-18783
Publication Date(Web):October 7, 2009
DOI:10.1021/jp905720g
TiO2 nanocrystal colloids with different shapes and sizes have been prepared from a peroxotitanate complex solution starting from titanium(IV) sulfate and hydrogen peroxide (H2O2) in water/alcohol media by a solvothermal process. The TiO2 nanocrystals were characterized by transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, FT-IR spectroscopy, zeta potential, and nitrogen adsorption. The TiO2 nanocrystal colloids prepared by a solvothermal process at 120 °C show a highly crystallized anatase phase. The particle sizes decreased with the increase of the alcohol/water ratio. The shapes of the particles have been controlled from the “rodlike” in pure water solvent to a “rectangular” shape in pure ethanol solvent. The photocatalytic activities of TiO2 nanocrystals were evaluated by the degradation of phenol. The photocatalytic activity of the anatase nanocrystal was closely related to the particle diameter. In addition, the possible growth mechanism of this anatase was illustrated.
Co-reporter:Chunhua Ge;Peng Ding;Liyi Shi;Jifang Fu
Journal of Polymer Science Part B: Polymer Physics 2009 Volume 47( Issue 7) pp:655-668
Publication Date(Web):
DOI:10.1002/polb.21669
Abstract
Poly(ethylene terephthalate) (PET)/Barite nanocomposites were prepared by direct melt compounding. The effects of PET-Barite interfacial interaction on the dynamic mechanical properties and crystallization were investigated by DMA and DSC. The results showed that Barite can act as a nucleating agent and the nucleation activity can be increased when the Barite was surface-modified (SABarite). SABarite nanoparticles induced preferential lamellae orientation because of the strong interfacial interaction between PET chains and SABarite nanoparticles, which was not the case in Barite filled PET as determined by WAXD. For PET/Barite nanocomposites, the Avrami exponent n increased with increasing crystallization temperature. Although at the same crystallization temperature, the n value will decrease with increasing SABarite content, indicating of the enhancement of the nucleation activity. Avrami analyses suggest that the nucleation mechanism is different. The activation energy determined from Arrhenius equation reduced dramatically for PET/SABarite nanocomposite, confirming the strong interfacial interaction between PET chains and SABarite nanoparticles can reduce the crystallization free energy barrier for nucleus formation. In the DSC scan after isothermal crystallization process, double melting behavior was found. And the double endotherms could be attributed to the melting of recrystallized less perfect crystallites or the secondary lamellae produced during different crystallization processes. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 655–668, 2009
Co-reporter:Shu-Ping Zhang, Yi Zheng, Lian-Gang Shan, Li-yi Shi, Kai-liang Leng
Applied Surface Science 2008 Volume 255(Issue 2) pp:439-441
Publication Date(Web):15 November 2008
DOI:10.1016/j.apsusc.2008.06.075
Abstract
A new and complex modification technique of glassy carbon electrode (GCE) with multi-walled carbon nanotubes (MWNTs) was developed. Firstly, MWNTs were electro-deposited on GCE at 1.70 V for 2 h. Secondly, by layer-by-layer (LBL) self-assembly technique, a functional membrane of {PDDA/MWNTs}n were fabricated by alternative immersion in 1% PDDA solution and 1 mg L−1 MWNTs dispersion either. As a result, the modified membrane with five {PDDA/MWNTs} bilayers have good sensitivity, stability, anti-fouling ability and catalytic activity for thiocholine (TCh) detection, the oxidation potential on the modified GCE was decreased almost by 50% while the peak current was increased almost by 100% compared with that on bare GCE. Meanwhile, it showed a low detection limit of less than 7.500 × 10−7 mol L−1 TCh.
Co-reporter:Shu Ping Zhang, Lian Gang Shan, Zhen Ran Tian, Yi Zheng, Li Yi Shi, Deng Song Zhang
Chinese Chemical Letters 2008 Volume 19(Issue 5) pp:592-594
Publication Date(Web):May 2008
DOI:10.1016/j.cclet.2008.03.014
The paper describes a controllable layer-by-layer (LBL) self-assembly modification technique of multi-walled carbon nanotubes (MWNTs) and poly(diallyldimethylammonium chloride) (PDDA) towards glassy carbon electrode (GCE), Acetylcholinesterase (AChE) was immobilized directly to the modified GCE by LBL self-assembly method, the activity value of AChE was detected by using i-t technique based on the modified Ellman method. Then the composition of carbaryl were detected by the enzyme electrode with 0.01U activity value and the detection limit of carbaryl is 10−12 g L−1 so the enzyme biosensor showed good properties for pesticides residue detection.
Co-reporter:Peng Ding, Baojun Qu, Liyi Shi, Chunhua Ge, Hui Yang
Materials Letters 2008 Volume 62(Issue 23) pp:3815-3817
Publication Date(Web):31 August 2008
DOI:10.1016/j.matlet.2008.04.073
We report a novel approach to assembling layered double hydroxide (LDH) into uniform dendritic nanostructures, called nanotrees, in bulk aqueous solution. The key factor of this method lies in the use of inorganic iron hydroxide colloid (IHC), acting as templates to stabilize the LDH layers and gluing them into nanotrees. In this approach, traditional organic templates, such as sodium dodecyl sulfate and urea, are completely avoided. The obtained LDH nanotrees readily show exfoliation properties and can be completely delaminated after modification with silane.
Co-reporter:Li Li, Liyi Shi, Shaomei Cao, Yu Zhang, Yuan Wang
Materials Letters 2008 Volume 62(12–13) pp:1909-1912
Publication Date(Web):30 April 2008
DOI:10.1016/j.matlet.2007.10.039
Spherical nano-sized YSZ (yttria stabilized ZrO2) powders were successfully synthesized via a reverse microemulsion system. The water droplets in the microemulsion system of yclohexane/water/span85/Triton X-100/hexyl alcohol can act as the nano-reactors which solubilize zirconium oxychloride and ammonia water separately. The minute original reactors are favor to the formation of nano-sized spherical YSZ powders and the dispersibility of the powders can be controlled effectually by adjusting the weight ratio of the LiNO3 molten salt to the precursor. The phase transformation from cubic to monoclinic starts at and 500 °C and finally monoclinic and cubic phase with increased crytallinity coexist at 800 °C. The effect of LiNO3 molten salt in the formation of YSZ powders was also discussed.
Co-reporter:Xin Feng, Liyi Shi, Shaofei Wang, Shurui Ma
Solid State Ionics 2008 Volume 179(Issue 37) pp:2077-2079
Publication Date(Web):15 November 2008
DOI:10.1016/j.ssi.2008.07.010
ZnO nanocrystallites were synthesized with the aids of NaNO3–KNO3 eutectic (45:55 wt.%) instead of any organic additives. X-ray powder diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM) were conducted. The characterization results indicated that the NaNO3–KNO3 eutectic, which acted as solvent medium, was in favor of the formation of homogeneous hexagonal ZnO nanocrystals.
Co-reporter:Jian Zhong Hang;Yu Fang Zhang;Li Yi Shi;Xin Feng
Journal of Materials Science 2007 Volume 42( Issue 23) pp:9611-9616
Publication Date(Web):2007 December
DOI:10.1007/s10853-007-1974-2
In this study, electrokinetic properties of barite nanoparticles have been investigated in water. A series of systematic zeta potential measurements have been performed to determine the isoelectric point (iep) and potential-determining ions (pdi), and the effect of mono-, di-, and trivalent anions sodium salts such as NaCl, NaNO3, NaCH3COO, Na2SO4, Na2CO3, and Na3PO4 on the zeta potential of barite nanoparticles. Barite nanoparticles yields an isoelectric point at pH 7.8. The zeta potential for the barite nanoparticles has ranged from +15.5 mV at pH ∼ 3 to −19.8 mV at pH ∼ 9.5 at 25 ± 1 °C in water. It is proved that the valency of the ions greatly influence on the electrokinetic behavior of the suspension. Monovalent anions were found to have a weak effect on the zeta potentials. The negative zeta potentials were observed in the presence of di- and trivalent anions. Charge reversal was observed for divalent anions at 1 × 10−2 M and for trivalent anions at 1 × 10−1 M. It was considered that monovalent anions are indifferent ions and di- and trivalent anions are potential-determining ions. A schematic adsorption model which accounts for the adsorption of mono- and multivalent anions in the electrical double layer of barite nanoparticles is proposed.
Co-reporter:Dan Shang, Xiaoying Sun, Jianzhong Hang, Lujiang Jin, Liyi Shi
Progress in Organic Coatings (April 2017) Volume 105() pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.porgcoat.2017.01.015
•Low-hydroxyl-content sols (LHCS) were synthesized by an anhydrous sol-gel method.•LHCS can improve flame retardancy of UV-curable coatings overall.•LHCS can upgrade physical and mechanical properties of UV-curable coatings.•LHCS can be directly added into the commercialized UV-curable coating formula.•LHCS is more practical than a UV-curable phosphorus-bearing flame retardant.As one of a series of our studies, starting with silica sol (TM2) and Si-P binary sol (SP5), two series of low-hydroxyl-content sols (LHCSs) were synthesized using an anhydrous sol-gel method. The stable storage time of LHCS-containing hybrid coatings was improved relative to that of hybrid coatings containing TM2 and SP5. The flame resistance and thermal stability of UV-cured hybrid coatings consisting of LHCS, epoxy acrylate of bisphenol A (SM6104) and tripropylene glycol diacrylate (TPGDA) were investigated by means of thermogravimetric analysis (TGA), limit oxygen index (LOI), cone calorimetry and a flammability test. The results indicated that the flame resistance of LHCS-containing hybrid coatings was further improved over that of hybrid coatings containing TM2 and SP5. The improvements mainly included a longer ignition time and lower combustion heat. Hybrid coatings applied on the surface of wooden floors could offer long-lasting and significant protection against fire, showing outstanding practical value. In addition, the physical and mechanical properties of LHCS-containing hybrid coatings were negatively affected by the decrease of hydroxyl group contents and the Ti-containing component. A UV-curable phosphorus-containing resin (RAYLOK 1722) was introduced into the hybrid coatings containing LHCS. However, hybrid coatings containing RAYLOK 1722 showed only a small improvement in flame resistance, and their physical and mechanical properties were damaged by RAYLOK 1722.
Co-reporter:Dengsong Zhang, Yilei Qian, Liyi Shi, Hailing Mai, Ruihua Gao, Jianping Zhang, Weijun Yu, Weiguo Cao
Catalysis Communications (5 September 2012) Volume 26() pp:164-168
Publication Date(Web):5 September 2012
DOI:10.1016/j.catcom.2012.05.001
The Cu-doped CeO2 spheres were synthesized by a simple hydrothermal method. It is confirmed that the spheres composed of many tiny particles are favorable for the gas diffusion in the inner pores. The doping copper is demonstrated to increase the storage and mobility of oxygen vacancy, surface area, and chemisorption sites for CO and enhance the redox capability, which can efficiently convert CO to CO2 at low temperature. The excellent catalytic performance of Cu (10 at.%)-doped CeO2 spheres are associated with the porous spherical structure, high redox capability and high oxygen vacancy.Download full-size imageHighlights► Cu-doped CeO2 spheres were synthesized by a simple hydrothermal method. ► The spheres consist of many tiny particles. ► The doping copper increases the redox capability and chemisorption sites for CO. ► The excellent catalytic activity is associated with the porous spherical structures.
Co-reporter:Yin Zhao, Jia Liu, Liyi Shi, Shuai Yuan, Jianhui Fang, Zhuyi Wang, Meihong Zhang
Applied Catalysis B: Environmental (11 October 2010) Volume 100(Issues 1–2) pp:
Publication Date(Web):11 October 2010
DOI:10.1016/j.apcatb.2010.07.013
The preparation of Ti1−xSnxO2 nanocrystal colloids from peroxo-metal precursor by hydrothermal method was reported in this work. The obtained materials were investigated by means of XRD, Raman, TEM, XPS, ICP-AES, N2 adsorption–desorption measurements (BET), PL and UV–vis spectroscopies technology. Photocatalytic degradation of phenol was studied under UV illumination. The results indicated that Ti1−xSnxO2 nanocrystal colloids were obtained in the nanometer scale (less than 10 nm) and the crystallite size was smaller than pure TiO2. Anatase phase, mixture phase (anatase and rutile) and rutile phase of Sn-doped TiO2 samples were formed, when x < 0.04, 0.04 < x < 0.06 and x ≥ 0.06, respectively. The Sn4+ dopants presented substitution Ti4+ into the lattice of TiO2 alongside increasing the surface oxygen vacancies and the surface hydroxyl groups. Regarding photocatalytic activity, Sn-doped TiO2 samples (TiSn3) were nearly four times higher than undoped samples. This obvious beneficial effect could be attributed to high surface area, optimal crystalline phase and surface state modifications.Graphical abstractDownload full-size imageResearch highlights▶ Anatase, rutile and mixture phase of Ti1−xSnxO2 samples were formed by changing Sn/Ti ratio. ▶ Enhanced activity attributes to high surface area, optimal crystalline phase and surface state.
Co-reporter:Zheng Liu, Lining Sun, Fuyou Li, Qian Liu, Liyi Shi, Dengsong Zhang, Shuai Yuan, Tao Liu and Yannan Qiu
Journal of Materials Chemistry A 2011 - vol. 21(Issue 44) pp:NaN17618-17618
Publication Date(Web):2011/10/18
DOI:10.1039/C1JM13871E
A simple and versatile method was proposed for self-assembling magnetic nanoparticles and hydrophobic upconversion nanoparticles on to a mesoporous nanoprobe by the means of an electrostatic interaction and binding scheme. The hybrid nanoprobes showed good magnetic and near-infrared luminescent properties, and could be explored as biosensors.
Co-reporter:Dengsong Zhang, Tingting Yan, Liyi Shi, Zheng Peng, Xiaoru Wen and Jianping Zhang
Journal of Materials Chemistry A 2012 - vol. 22(Issue 29) pp:NaN14704-14704
Publication Date(Web):2012/05/24
DOI:10.1039/C2JM31393F
Graphene/carbon nanotube (GR/CNT) composites were prepared by a modified exfoliation approach and used as capacitive deionization (CDI) electrodes. SEM and TEM images demonstrate that the CNTs are successfully inserted into the GR. Nitrogen sorption analysis and electrochemical impedance spectroscopy show that the GR/CNT composites have a larger specific surface area and higher conductivity as compared with GR, which is due to the inserted CNTs inhibiting the aggregation and increasing the conductivity in the vertical direction. Through cyclic voltammetry and galvanostatic charge/discharge evaluation, we can conclude that the prepared composites have higher specific capacitance values and better stability, suggesting that the GR/CNT composite electrodes have a higher electrosorption capacity. Power and energy density analysis shows that the GR/CNT composite electrodes have higher power density and energy density and the energy density decay is relatively slow in a wide range of power as compared with GR, which indicates that the composite electrodes exhibit low energy consumption for capacitive deionization. The desalination capacity was evaluated by a batch mode electrosorptive experiment in a NaCl aqueous solution. As compared with GR and commercial activated carbon, the GR/CNT composite electrodes exhibit excellent desalination behavior, which is attributed to the improved electric conductivity and higher accessible surface area, which are quite beneficial for the electrosorption of ions onto the electrodes. The GR/CNT composites are confirmed to be promising materials for CDI electrodes.
Co-reporter:Hui Wang, Dengsong Zhang, Tingting Yan, Xiaoru Wen, Jianping Zhang, Liyi Shi and Qingdong Zhong
Journal of Materials Chemistry A 2013 - vol. 1(Issue 38) pp:NaN11789-11789
Publication Date(Web):2013/07/25
DOI:10.1039/C3TA11926B
In order to obtain excellent desalination behavior during the capacitive deionization (CDI) process, electrodes should provide efficient pathways for ion and electron transport. Here we open up a new opportunity to prepare high performance capacitive deionization (CDI) electrodes based on three-dimensional macroporous graphene architectures (3DMGA). The 3DMGA were fabricated by a simple template-directed method using polystyrene microspheres as sacrificial templates. The resulting 3DMGA exhibited a 3D interconnected structure with large specific surface area and high electric conductivity. The electrochemical behavior of the 3DMGA electrodes was analyzed by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. It was found that the 3DMGA showed superiority in electrosorption capacitance, low inner resistance, high reversibility and excellent stability. The power and energy density analysis further demonstrated that the 3DMGA electrode had a higher power output and lower energy consumption. According to the electrochemical measurements, the 3DMGA is quite desirable for high performance and low energy consumption capacitive deionization. The desalination capacity was evaluated by a batch mode electrosorptive experiment in a NaCl aqueous solution. An excellent desalination behavior of the 3DMGA was obtained due to the large accessible surface area, high electric conductivity and unique 3D interconnected macroporous structure. The 3DMGA was confirmed to be a promising material for CDI application.
Co-reporter:Yanyan Lou, Shuai Yuan, Yin Zhao, Pengfei Hu, Zhuyi Wang, Meihong Zhang, Liyi Shi and Dongdong Li
Dalton Transactions 2013 - vol. 42(Issue 15) pp:NaN5337-5337
Publication Date(Web):2013/01/17
DOI:10.1039/C3DT32741H
A molecular surface chemical treatment is introduced into a dye sensitized solar cell (DSSC) incorporating metal nanoparticles to suppress the charge recombination. Dodecanethiol molecules as a surface treatment agent are successfully anchored onto the exposed Au nanoparticle sites of the ZnO nanorods/Au nanoparticles/N719 photoanode. ATR-FTIR and Raman measurements are conducted to understand the adsorptions of different molecules (dodecanethiol, N719) on the ZnO nanorods and Au nanoparticles surface. The effects of the dodecanethiol surface treatment on the performance of the plasmon-enhanced DSSC are investigated by UV-vis absorption, incident photon-to-current conversion efficiency (IPCE) and electrochemical impedance spectroscopy (EIS). The plasmon-enhanced light absorption due to the presence of Au nanoparticles is not affected by the dodecanethiol surface treatment. The charge recombination on the ZnO nanorods–dye–electrolyte interface is substantially retarded by insulating the exposed Au nanoparticle sites from the oxidized form of the electrolyte via dodecanethiol molecules. The strategy of a molecular surface chemical treatment on the photoanode of a DSSC with metal nanoparticles fully exploits the plasmon-enhanced light absorption and explores a simple method to protect the metal nanoparticles for the plasmon-enhanced DSSC.
Co-reporter:Xianjun Du, Dengsong Zhang, Ruihua Gao, Lei Huang, Liyi Shi and Jianping Zhang
Chemical Communications 2013 - vol. 49(Issue 60) pp:NaN6772-6772
Publication Date(Web):2013/06/04
DOI:10.1039/C3CC42418A
The modular catalysts were fabricated via the combination of the Ni–MgO–Al2O3 mixed oxide nanoplates and the mesoporous SiO2 coating. Due to the dual confinements, the catalysts show high catalytic activity with enhanced coke- and sintering-resistance in the dry reforming of methane reaction.
Co-reporter:Yamin Feng, Qingbo Xiao, Yanhui Zhang, Fujin Li, Yanfang Li, Chunyan Li, Qiangbin Wang, Liyi Shi and Hongzhen Lin
Journal of Materials Chemistry A 2017 - vol. 5(Issue 3) pp:NaN510-510
Publication Date(Web):2016/12/05
DOI:10.1039/C6TB01961G
The achievement of efficient near-infrared (NIR) luminescence of lanthanide ions in a paramagnetic nanoparticle (NP) host is highly desirable to optimize the performance of multimodal bioprobes. Herein, we present a facile coprecipitation method to prepare highly uniform NaHoF4:Nd3+ nanoplates. Upon NIR excitation at 785 nm, efficient NIR luminescence of Nd3+ can be obtained from the paramagnetic NaHoF4 hosts. More interestingly, due to energy transfer from the excited state of Nd3+ to the adjacent Ho3+, NIR emission at around 1200 nm from Ho3+ ions is also observed. The r2 value of NaHoF4:Nd3+ NPs reaches 143.7 s−1 mM−1 at a high magnetic field of 11.7 T. By modifying with hydrophilic alpha-cyclodextrin, the NaHoF4:Nd3+ NPs were further successfully applied for the NIR luminescent/T2-weighted MR dual-modal in vivo imaging of nude mice, high contrast NIR imaging of the liver and T2-weighted MR imaging of stem cells in the mouse brain using the NaHoF4:Nd3+ NPs as multimodal bioprobes.
Co-reporter:Ruihua Gao ; Dengsong Zhang ; Phornphimon Maitarad ; Liyi Shi ; Thanyada Rungrotmongkol ; Hongrui Li ; Jianping Zhang ;Weiguo Cao
The Journal of Physical Chemistry C () pp:
Publication Date(Web):
DOI:10.1021/jp400984z
The morphology effect of ZrO2–CeO2 on the performance of MnOx/ZrO2–CeO2 catalyst for the selective catalytic reduction of NO with ammonia was investigated. The catalytic tests showed that the MnOx/ZrO2–CeO2 nanorods achieved significantly higher NO conversions than the nanocubes and nanopolyhedra. The catalytic tests also showed that the MnOx/ZrO2–CeO2 nanorods achieved a significantly higher rate constant with respect to NO conversion than that of the nanocubes and nanopolyhedra. On the nanorods, the apparent activation energy is 25 kJ mol–1, which was much lower than the values of nanocubes and nanopolyhedra (42 and 43 kJ mol–1). The high resolution transmission electron microscopy showed that the nanorods predominately exposed {110} and {100} planes. It was demonstrated that the ZrO2–CeO2 nanorods had a strong interaction with MnOx species, which resulted in great superiority for the selective catalytic reduction of NO. The excellent catalytic activity of the MnOx/ZrO2–CeO2 nanorods should be attributed to the Mn4+ species, adsorbed surface oxygen and oxygen vacancies which are associated with their exposed {110} and {100} planes.
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