Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 29
·15056-15064
·
IF 8.867
J. R. Zeng,M. Y. Gao,Q. B. Zhang,C. Yang,X. T. Li,W. Q. Yang,Y. X. Hua,C. Y. Xu,Y. Li
The development of low-cost, earth-abundant, and high-efficiency catalysts for electrocatalytic water splitting is central to developing sustainable and clean energy. The abundant reserves of nickel sulfides are promising noble metal-free materials for the hydrogen evolution reaction (HER). In this work, a highly active cauliflower-like S-doped nickel microsphere film directly grown on a copper wire (CW) substrate (labeled as NiSx/CW) was facilely prepared via a one-step electrodeposition approach in a choline chloride/ethylene glycol (ethaline)-based deep eutectic solvent. Doping of S is found to induce an interesting structural transition from nanosheets to porous cauliflower-like microspheres, electronic structure changes at the surface, and a significant improvement in the HER catalytic performance. The as-prepared NiS0.25/CW with a Ni/S atomic ratio of 1 : 0.25 exhibits the best performance, showing a negligible onset potential (−18 mV) with a low overpotential (−54 mV at 10 mA cm−2) and small Tafel slope (54 mV dec−1) in 1.0 M KOH solution. Additionally, the NiS0.25/CW catalyst displays good durability and affords long-term electrolysis without activity degradation for 60 h. This study offers a facile synthesis route for in situ growth of the active phases on current collectors to fabricate self-supported noble-metal free HER catalysts and deep insights into the relationships among the S-doping, catalyst microstructure, and catalytic properties.
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2016
·
IF 3.12
Wen-jun Liang,Bin Zhao,Pei-hua Zhao,Cong-yun Zhang,Ya-qing Liu
A novel bridged-cyclotriphosphazene flame retardant , named bisphenol-S bridged penta(anilino)cyclotriphosphazene (BPS-BPP), was synthesized and characterized by fourier transform infrared (FTIR), 1 H NMR and 31 P NMR and mass spectroscopy (MS). Then, BPS-BPP was used to flame retard epoxy resin (EP, diglycidyl ether of bisphenol-A type). The curing behavior and glass-transition temperature (T g ) of EP/BPS-BPP were investigated by differential scanning calorimetry (DSC). The thermogravimetric analysis (TGA) results showed that the incorporation of BPS-BPP improved the thermal stability of EP at high temperature region. Limiting oxygen index (LOI) value of EP sample increased to 29.7% with limited amount of 9 wt% BPS-BPP. The peak of heat release rate (PHRR), total heat release (THR), total smoke production (TSP) values of the same sample, obtained from cone calorimetry , were declined conspicuously, indicating good flame-retardant and smoke suppression efficiency of BPS-BPP. The flame-retardant mechanism of EP/BPS-BPP thermosets was investigated via analyses of gaseous products and char residues. Based on the aforementioned studies, BPS-BPP was demonstrated as an effective flame retardant for EP due to temperature-dependent and bi-phase flame retardant mechanism.
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2016
·
IF 2.628
Dun Deng,Yun Zhang,Aijun Sun,Yunfeng Hu
We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions. Herein, we have investigated the use of MT6 in stereo-selective biocatalysis through direct hydrolysis reactions. Notably, the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions. Parameters, including temperature, organic co-solvents, pH, ionic strength, catalyst loading, substrate concentration, and reaction time, affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated, with the e.e. of the final ( S )-1-Phenylethanol product and the conversion being 97% and 28.5%, respectively, after process optimization. The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions. MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 23
·期 9
·8976-8984
·
IF 2.76
Guo Huiying,Li Hao,Liang Ni,Chen Fangyuan,Liao Shaohua,Zhang Di,Wu Min,Pan Bo
Bisphenol S (BPS), a new bisphenol analog, is considered to be a potential replacement for bisphenol A (BPA), which has gained concern because of its potentially adverse health impacts. Therefore, studies are needed to investigate the environmental fate and risks of this compound. In this study, the adsorption of BPS and four structural analogs on multi-walled carbon nanotubes (MWCNTs) and graphite (GP) were investigated. When solid-phase concentrations were normalized by the surface areas, oxygen-containing functional groups on the absorbents showed a positive impact on phenol sorption but inhibited the sorption of chemicals with two benzene rings. Among BPS analogs, diphenyl sulfone showed the lowest sorption when hydrophobic effects were ruled out. Chemicals with a butterfly structure, formed between the two benzene rings, showed consistently high sorption on MWCNTs, independent of the substituted electron-donating or accepting functional groups. This study emphasizes the importance of chemical conformation on organic, contaminant sorption on engineered, carbonaceous materials.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
HIGH PERFORMANCE POLYMERS
·
2016
·
IF 1.045
Lan Li,Jiangtao Liu,Guofei Chen,Lubo Xu,Nafeesa Mushtaq,Lala Rukh Sidra,Ruixin Wang,Xingzhong Fang
A series of cardo poly(ether sulfone imide)s (PESI-C) containing bulky phthalide groups were prepared via aromatic nucleophilic substitution reaction of phenolphthalein with 4,4′-difluorodiphenyl sulfone and 4,4′-bis(4-fluorophthalimido)diphenyl ether (BFPI). The glass transition temperatures and 5% weight loss temperatures in nitrogen of the resulting PESI-C increased from 258°C to 278°C and from 468°C to 495°C with increasing the content of imide moiety in the polymer chain, respectively. These PESI-C films were transparent and essentially colorless and exhibited good mechanical properties with tensile strengths of 91–124 MPa, elongations at break of 6.9–12.8%, and tensile moduli of 2.2–2.8 GPa, respectively. It is noted that the tensile strengths, elongations at break, and tensile moduli of PESI-C also increased with increasing the content of BFPI in the copolymerization, indicating that the properties could be adjusted by controlling the ratio of BFPI and 4,4′-difluorodiphenyl sulfone.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 101
·98854-98860
·
IF 3.289
Guibin Li,Chengji Zhao,Chongyi Zhu,Chunyu Ru,Xuefeng Li,Duo Qi,Yuxue Wei,Hui Na
Novel side-chain-type naphthalene-based poly(aryl ether ketones) with quaternary ammonium groups (Q-SCT-NPAEK) were synthesized and doped with phosphoric acid (PA), which can be used as potential high temperature proton exchange membranes. The PA doped Q-SCT-NPAEK membranes showed high thermal stabilities and high glass transition temperatures (Tg > 228 °C). They all have high tensile strengths, which were higher than 72 MPa. The introduction of a naphthalene moiety greatly improves the PA doped membranes' mechanical and thermal stabilities, which are much better than the commonly reported PA doped polybenzimidazole membrane. PA doped Q-SCT-NPAEK-100% with the highest IEC exhibits the highest weight uptake (635 wt%), doping level (16.6) and proton conductivity (46 mS cm−1 at 160 °C). Interestingly, these PA doped membranes still possess high thermal and mechanical stabilities, reaching up to 285 °C (T5%) and 15 MPa, respectively.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2013
·Vol. 24
·期 9
·807-813
·
IF 1.635
Tao Han,Yi Zhang,Qiaoying Cao,Siwei Liu,Zhenguo Chi,Jiarui Xu
A series of novel optically active poly(ester-imide)s (ter-PEIs) with high glass transition temperature ( T g ), good thermal stability, and solubility were successfully designed and synthesized by direct polycondensation reactions, using p-hydroxybenzoic acid (PHB), 4,4’-dihydroxybenzophenone, and a chiral diacid, N , N '-(pyromellitoyl)-bis-L-phenylalanine diacid as monomers. The resulting terpolymers were characterized by 1 H-NMR, FTIR, element analysis, thermogravimetric analysis, different scanning calorimeter and wide-angle x-ray diffraction, etc. The ter-PEIs are amorphous polymers with good heat resistance and high T g s. They are soluble in many common polar organic solvents and show optically rotation property. The specific rotation values of the ter-PEIs increase with the molar ratio of the chiral diacid, and the rigid PHB monomer is beneficial to increase the T g s of the polymers. Copyright © 2013 John Wiley & Sons, Ltd.
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2015
·Vol. 3
·期 3
·360-367
·
IF 4.062
Dan Qu,Zaicheng Sun,Min Zheng,Jing Li,Yongqiang Zhang,Guoqiang Zhang,Haifeng Zhao,Xingyuan Liu,Zhigang Xie
A facile solvothermal route to synthesize S,N co-doped graphene quantum dots (S,N-GQDs) with unique optical properties is demonstrated. Three absorption bands are observed at 338, 467, and 557 nm, which is different from any previous reports. The photoluminescent spectra display emissions in three primary colors that are independent of the excitation wavelength, within the excitation wavelength ranges of 340–420 nm, 460–540 nm, and 560–620 nm. The PL excitation spectra indicate that each emission is related to a single excitation band. It is proposed that three independent luminescent centers coexist in S,N-GQDs because the doping with S and N may change the chemical environment of the GQDs. However, energy-transfer processes usually do not occur among the independent luminescent centers under different wavelength light excitation. Heteroatom-doping of GQDs provides an attractive means of effectively tuning their optical properties for the purpose of exploiting new applications in visible-light photocatalytic and bioimaging. S,N-GQDs/TiO 2 composites exhibit better hydrogen production activities under visible light ( λ > 420 nm) than commercial TiO 2 (P25), owing to the presence of characteristic absorption bands in the visible region. Furthermore, the S,N-GQDs have a pronounced biocompatibility and bioimaging ability under long-wavelengths excitation for live A549 cells.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2015
·
IF 5.056
Yi Zhi Zhuo,Ao Nan Lai,Qiu Gen Zhang,Ai Mei Zhu,Mei Ling Ye,Qing Lin Liu
Anion exchange membrane fuel cells (AEMFCs) have become one of the most promising energy-conversion devices due to the potential of adopting non-noble metal catalysts and faster oxygen reduction reaction kinetics in an alkaline operating environment. Here, a series of anion exchange membranes with high ionic-conductivity and low swelling ratio were prepared from imidazolium-functionalized crosslinked cardo poly(arylene ether sulfone)s for AEMFCs. Two oligomers, tertiary amine-containing poly(arylene ether sulfone) (PES-DA) and bromomethyl-containing poly(arylene ether sulfone) (BPES), are synthesized and then mixed at −40 °C. They are spontaneously inter-crosslinked at room temperature to form dense anion exchange membranes (AEMs), in which the tertiary amine groups of PES-DA rapidly react with the bromomethyl groups of BPES to form the crosslinked bonds. This avoids the use of crosslinking agents and the expense of functional groups. The resulting membranes show a high hydroxide conductivity up to 82.4 mS cm −1 at 80 °C and a slight swelling low to traditional AEMs due to its crosslinked network structure. An open circuit voltage (OCV) of 0.82 V and a maximum power density of 92.1 mW cm −2 are achieved in a H 2 /O 2 single cell. The as-prepared membranes have a great potential for the application in AEMFCs.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Mao Zhou,Ruizhuo Ouyang,Yuhao Li,Yuqing Miao
3D microspheres from the in situ synthesis, growth and organization of Ni-Mo-S nanoparticles (NPs) on porous Ti plate were obtained through a typical hydrothermal method . The Ni-Mo-S/Ti electrode exhibited excellent electrocatalytic performance for hydrogen evolution reaction (HER) in strong acid electrolyte. HER occurs at the relatively low onset potential of −4 mV with high current of 10 mA/cm 2 at low overpotential of 30 mV in 0.5 M H 2 SO 4 . Furthermore, the Ni-Mo-S/Ti exhibited excellent electrocatalytic stability over an extended period of 60000 s without obvious current decrease observed. The multinary composition , 3D microsphere-like structure from nanoparticles, porous supporting substrate, the good conductivity of Ti and good electron transfer between electrode and catalysts, all of them are combined to contribute to the high HER electrocatalytic activity of the Ni-Mo-S/Ti. The good stability comes from the stability of catalysts and Ti themselves, and the tight contact between catalysts and supporting electrode.
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2016
·Vol. 7
·期 48
·7427-7435
·
IF 5.687
Nafeesa Mushtaq,Guofei Chen,Lala Rukh Sidra,Yang Liu,Xingzhong Fang
Two novel series of highly organosoluble and curable polyimides containing pendant nitrile groups PI (a–d) and phthalonitrile-terminated polyimides PN-PI (a–d) were prepared by solution polycondensation of isomeric bis(chlorophthalimides)s and 2,6-dichlorobenzonitrile with 4,4′-thiobisbenzenethiol. The inherent viscosities of these copolymers were in the range of 0.37–0.59 dL g−1 in N-methyl-2-pyrrolidone (NMP) at 30 °C. The phthalonitrile and pendant nitrile groups in isomeric poly(thioether-ether-imide)s were thermally crosslinked without a catalyst through thermal curing up to 280–360 °C, which led to the transformation from thermoplastic polymers to thermosetting polymers. All PIs before and after crosslinking were characterised by gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. PN-PI (a–d) and PI (a–d) were found to be highly soluble in some solvents, such as chloroform, dimethylacetamide, m-cresol, dimethlyformamide and N-methyl-2-pyrrolidone, while the crosslinked polymers were insoluble in all tested solvents. The crosslinking results of pendant nitrile and terminal phthalonitrile groups are also compared. Both series of PIs showed high thermal stability based on 5% weight loss temperature (T5%) in the range of 471–509 °C and increased up to 35 °C after thermal curing. Polyimides showed high glass transition temperatures (Tgs) ranging from 191–213 °C as determined by DSC, but no detectable Tg was observed after thermal heating, indicating the crosslinked structure of PIs. The mechanical properties also enhanced after the crosslinking of the copolymers. The tensile modulus and strength of the cured PI films were in the range of 3.3–4.7 GPa and 68–122 MPa, respectively, which were up to 62% and 35% higher than the uncured films.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 5
·期 1
·536-544
·
IF 3.708
Baolong Wang,Zhenzhen Cai,Na Zhang,Bin Zhang,Duo Qi,Chengji Zhao,Hui Na
A series of sulfonated naphthalene-based poly (arylene ether ketone)s (SNPAEK-xx) with pendant sulfoalkyl groups were prepared by polycondensation of 1,5-bis(4-fluorobenzoyl)-2,6-dimethoxynaphthalene and o-methylhydroquinone, followed by a demethylation and sulfobutylation reaction. The sulfonate degree of SNPAEK-xx could be controlled easily by adjusting the ratio of 1,4-butane sultone to the hydroxyl content in the demethylated polymers. Flexible and tough membranes with reasonably high mechanical strength were prepared. SNPAEK-xx membranes showed a high ionic exchange capacity (IEC) in the range of 1.13 to 2.27 mequiv. g−1, and the highest proton conductivity of 0.191 S cm−1 at 80 °C. They exhibited low methanol permeability in the range of 1.25–10.22 × 10−7 cm2 s−1, which was much lower than that of Nafion 117. Transmission electron microscopy analysis of SNPAEK-xx revealed that they had a more obvious phase separated structure between the hydrophilic side chain and hydrophobic fully aromatic domains at a higher IEC. Combining their high thermal and mechanical stability, high selectivity, lower water swelling ratio, SNPAEK-xx membranes could be promising materials as alternative to Nafion membranes for direct methanol fuel cell applications.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）