Compound Zn2Sn0.8Ti0.2O4 was synthesized by a hydrothermal method in which SnCl4-5H2O,TiCl4,ZnCl2 and N2H4-H2O were used as reactants.The composite Zn2Sn0.8Ti0.2O4/C was then prepared through a carbothermic reduction ...Compound Zn2Sn0.8Ti0.2O4 was synthesized by a hydrothermal method in which SnCl4-5H2O,TiCl4,ZnCl2 and N2H4-H2O were used as reactants.The composite Zn2Sn0.8Ti0.2O4/C was then prepared through a carbothermic reduction process using the as-prepared Zn2Sn0.8Ti0.2O4 and glucose as reactants.The structure,morphology and electrochemical properties of the as-prepared products were investigated by XRD,XPS,TEM and electrochemical measurements.In addition,electrochemical Li insertion/extraction in composite Zn2Sn0.8Ti0.2O4/C were examined by ex situ XRD and SEM.The first discharge capacity of Zn2SnO4 is about 1670.8 mA-h/g,with a capacity retain of 342.7 mA-h/g in the 40th cycle at a constant current density of 100 mA/g in the voltage range of 0.05-3.0 V.Comparing with the Zn2SnO4,some improved electrochemical properties are obtained for Zn2Sn0.8Ti0.2O4,Zn2SnO4/C and Zn2Sn0.8Ti0.2O4/C.The composite Zn2Sn0.8Ti0.2O4/C shows the best electrochemical properties,and its first discharge capacity is about 1530.0 mA-h/g,with a capacity retain of 479.1 mA-h/g the 100th cycle.展开更多
采用化学沉淀法,并通过进一步的水热反应,制备得到纳米二氧化锡颗粒,通过TEM分析知纳米二氧化锡颗粒的粒径约为5 nm;通过2,4-二羟基苯甲酸和甲醛之间的缩合反应,在体系中加入纳米二氧化锡颗粒,再通过水洗和热处理等步骤制备了纳米SnO_2/...采用化学沉淀法,并通过进一步的水热反应,制备得到纳米二氧化锡颗粒,通过TEM分析知纳米二氧化锡颗粒的粒径约为5 nm;通过2,4-二羟基苯甲酸和甲醛之间的缩合反应,在体系中加入纳米二氧化锡颗粒,再通过水洗和热处理等步骤制备了纳米SnO_2/C碳包覆微球,控制加入二氧化锡纳米颗粒的质量制备了不同样品来探究其对材料形貌及性能的影响。研究表明,当添加纳米二氧化锡含量为40%时,纳米SnO_2/C复合材料的电化学性能最佳。在电流密度为100 m A/g充放电时,首次可逆比容量为825.2 m Ah/g,第100次循环的可逆比容量为593.2 m Ah/g,容量保持率达71.9%。展开更多
PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction method.These electrocatalysts were characterized by EDX,X-ray diffracti...PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction method.These electrocatalysts were characterized by EDX,X-ray diffraction,transmission electron microscopy and the catalytic activity toward formic acid electro-oxidation in acid medium investigated by cyclic voltammetry(CV),chroamperometry(CA)and tests on direct formic acid fuel cell(DFAFC)at 100℃.X-ray diffractograms of PdAuIr/C-Sb2O5·SnO2electrocatalysts showed the presence of Pd fcc phase,Pd-Au fcc alloys,carbon and ATO phases,while Ir phases were not observed.TEM micrographs and histograms indicated that the nanoparticles were not well dispersed on the support and some agglomerates.The cyclic voltammetry and chroamperometry studies showed that PdAuIr/C-Sb2O5·SnO2(50∶45∶5)had superior performance toward formic acid electro-oxidation at 25℃compared to PdAuIr/C-Sb2O5·SnO2(70∶20∶10),PdAuIr/C-Sb2O5·SnO2(90∶5∶5)and Pd/C-Sb2O5·SnO2electrocatalysts.The experiments in a single DFAFC also showed that all PdAuIr/C-Sb2O5·SnO2electrocatalysts exhibited higher performance for formic acid oxidation in comparison with Pd/C-Sb2O5·SnO2electrocatalysts,however PdAuIr/C-Sb2O5·SnO2(90∶5∶5)had superior performance.These results indicated that the addition of Au and Ir to Pd favor the electro-oxidation of formic acid,which could be attributed to the bifunctional mechanism(the presence of ATO,Au and Ir oxides species)associated to the electronic effect(Pd-Au fcc alloys).展开更多
PtSn2-SnO2/C nanocatalyst was prepared by co-reduction of Pt and Sn precursor at ca,15℃.The formation of PtSn2-SnO2 nanoparticle was determined by XRD,TEM and XPS characterization.This PtSn2-SnO2/C nanocatalyst exhib...PtSn2-SnO2/C nanocatalyst was prepared by co-reduction of Pt and Sn precursor at ca,15℃.The formation of PtSn2-SnO2 nanoparticle was determined by XRD,TEM and XPS characterization.This PtSn2-SnO2/C nanocatalyst exhibits stronger resistance to CO poisoning and effectively improves methanol electro-catalytic effect,up to 3 times than the commercial Pt/C catalyst.展开更多
Carbon-supported Pt/C,Pt/Re/C,Pt/SnO2/C and Pt/Re/SnO2/C,with 20 wt.%overall metal loading were prepared and their electrochemical activity towards ethanol oxidation reaction(EOR)was investigated.Transmission electron...Carbon-supported Pt/C,Pt/Re/C,Pt/SnO2/C and Pt/Re/SnO2/C,with 20 wt.%overall metal loading were prepared and their electrochemical activity towards ethanol oxidation reaction(EOR)was investigated.Transmission electron microscopy(TEM)combined with energy dispersive X-ray spectroscopy(EDS)revealed,that indeed binary and ternary combinations of the designed nanoparticles(NPs)were formed and successfully uniformly deposited on a carbon support.Fourier transform infrared spectroscopy(FTIR)allowed to assess the chemical composition of the nanocatalysts and X-ray diffraction(XRD)allowed to determine the catalyst structure.Potentiodynamic and chronoamperometric measurements were used to establish its catalytic activity and stability.The influence of Re addition on the electrochemical activity towards ethanol oxidation reaction(EOR)was verified.Indeed,the addition of Re to the binary Pt/SnO2/C catalyst leads to the formation of ternary Pt/Re/SnO2/C with physical contact between the individual NPs,enhancing the EOR.Furthermore,the onset potential of the synthesized ternary catalyst is shifted to more negative potentials and the current densities and specific activity are nearly 11 and 5 times higher,respectively,than for commercial Pt catalyst.Additionally ternary Pt/Re/SnO2/C catalyst retained 96%of its electrochemical surface area.展开更多
An extended-gate field effect transistor (EGFET)of SnO_2/ITO glass was applied to manufacture the vitamin C sensor.Therefore,we immobilized the ascorbate oxidase with 3-glycidoxypropyltrimethoxysilane (GPTS)method to ...An extended-gate field effect transistor (EGFET)of SnO_2/ITO glass was applied to manufacture the vitamin C sensor.Therefore,we immobilized the ascorbate oxidase with 3-glycidoxypropyltrimethoxysilane (GPTS)method to measure the different concentrations of the vitamin C solution in an optimum measurement environment.In order to find the best measurement conditions of the biosensor,we studied the vitamin C sensor in different pH values of the phosphate buffer solution (PBS).Additionally,we used experimental results to discuss the response time and response voltage to compare vitamin C with orange juice for the vitamin C sensor.展开更多
基金Project (51004028) supported by the National Natural Science Foundation of China
文摘Compound Zn2Sn0.8Ti0.2O4 was synthesized by a hydrothermal method in which SnCl4-5H2O,TiCl4,ZnCl2 and N2H4-H2O were used as reactants.The composite Zn2Sn0.8Ti0.2O4/C was then prepared through a carbothermic reduction process using the as-prepared Zn2Sn0.8Ti0.2O4 and glucose as reactants.The structure,morphology and electrochemical properties of the as-prepared products were investigated by XRD,XPS,TEM and electrochemical measurements.In addition,electrochemical Li insertion/extraction in composite Zn2Sn0.8Ti0.2O4/C were examined by ex situ XRD and SEM.The first discharge capacity of Zn2SnO4 is about 1670.8 mA-h/g,with a capacity retain of 342.7 mA-h/g in the 40th cycle at a constant current density of 100 mA/g in the voltage range of 0.05-3.0 V.Comparing with the Zn2SnO4,some improved electrochemical properties are obtained for Zn2Sn0.8Ti0.2O4,Zn2SnO4/C and Zn2Sn0.8Ti0.2O4/C.The composite Zn2Sn0.8Ti0.2O4/C shows the best electrochemical properties,and its first discharge capacity is about 1530.0 mA-h/g,with a capacity retain of 479.1 mA-h/g the 100th cycle.
文摘采用化学沉淀法,并通过进一步的水热反应,制备得到纳米二氧化锡颗粒,通过TEM分析知纳米二氧化锡颗粒的粒径约为5 nm;通过2,4-二羟基苯甲酸和甲醛之间的缩合反应,在体系中加入纳米二氧化锡颗粒,再通过水洗和热处理等步骤制备了纳米SnO_2/C碳包覆微球,控制加入二氧化锡纳米颗粒的质量制备了不同样品来探究其对材料形貌及性能的影响。研究表明,当添加纳米二氧化锡含量为40%时,纳米SnO_2/C复合材料的电化学性能最佳。在电流密度为100 m A/g充放电时,首次可逆比容量为825.2 m Ah/g,第100次循环的可逆比容量为593.2 m Ah/g,容量保持率达71.9%。
基金the Laboratório de Microscopia do Centro de Ciências e Tecnologia de Materiais(CCTM) by TEM measurements,FAPESP(2011/18246-0,2012/03516-5) and CNPQ(150639/2013-9)for the financial support
文摘PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction method.These electrocatalysts were characterized by EDX,X-ray diffraction,transmission electron microscopy and the catalytic activity toward formic acid electro-oxidation in acid medium investigated by cyclic voltammetry(CV),chroamperometry(CA)and tests on direct formic acid fuel cell(DFAFC)at 100℃.X-ray diffractograms of PdAuIr/C-Sb2O5·SnO2electrocatalysts showed the presence of Pd fcc phase,Pd-Au fcc alloys,carbon and ATO phases,while Ir phases were not observed.TEM micrographs and histograms indicated that the nanoparticles were not well dispersed on the support and some agglomerates.The cyclic voltammetry and chroamperometry studies showed that PdAuIr/C-Sb2O5·SnO2(50∶45∶5)had superior performance toward formic acid electro-oxidation at 25℃compared to PdAuIr/C-Sb2O5·SnO2(70∶20∶10),PdAuIr/C-Sb2O5·SnO2(90∶5∶5)and Pd/C-Sb2O5·SnO2electrocatalysts.The experiments in a single DFAFC also showed that all PdAuIr/C-Sb2O5·SnO2electrocatalysts exhibited higher performance for formic acid oxidation in comparison with Pd/C-Sb2O5·SnO2electrocatalysts,however PdAuIr/C-Sb2O5·SnO2(90∶5∶5)had superior performance.These results indicated that the addition of Au and Ir to Pd favor the electro-oxidation of formic acid,which could be attributed to the bifunctional mechanism(the presence of ATO,Au and Ir oxides species)associated to the electronic effect(Pd-Au fcc alloys).
基金The project was supported by the National Natural Science Foundation of China(No.20871107)He'nan Outstanding Youth Science Fund(No.0612002700)the Natural Science Foundation of the Education of Henan province(No.2009A150031)
基金supported by NSFC (Nos. 21373116 and 21421001)the Tianjin Natural Science Research Fund (No. 13JCYBJC18300)+1 种基金RFDP (No. 20120031110005)the MOE Innovation Team (No. IRT13022) of China
文摘PtSn2-SnO2/C nanocatalyst was prepared by co-reduction of Pt and Sn precursor at ca,15℃.The formation of PtSn2-SnO2 nanoparticle was determined by XRD,TEM and XPS characterization.This PtSn2-SnO2/C nanocatalyst exhibits stronger resistance to CO poisoning and effectively improves methanol electro-catalytic effect,up to 3 times than the commercial Pt/C catalyst.
文摘Carbon-supported Pt/C,Pt/Re/C,Pt/SnO2/C and Pt/Re/SnO2/C,with 20 wt.%overall metal loading were prepared and their electrochemical activity towards ethanol oxidation reaction(EOR)was investigated.Transmission electron microscopy(TEM)combined with energy dispersive X-ray spectroscopy(EDS)revealed,that indeed binary and ternary combinations of the designed nanoparticles(NPs)were formed and successfully uniformly deposited on a carbon support.Fourier transform infrared spectroscopy(FTIR)allowed to assess the chemical composition of the nanocatalysts and X-ray diffraction(XRD)allowed to determine the catalyst structure.Potentiodynamic and chronoamperometric measurements were used to establish its catalytic activity and stability.The influence of Re addition on the electrochemical activity towards ethanol oxidation reaction(EOR)was verified.Indeed,the addition of Re to the binary Pt/SnO2/C catalyst leads to the formation of ternary Pt/Re/SnO2/C with physical contact between the individual NPs,enhancing the EOR.Furthermore,the onset potential of the synthesized ternary catalyst is shifted to more negative potentials and the current densities and specific activity are nearly 11 and 5 times higher,respectively,than for commercial Pt catalyst.Additionally ternary Pt/Re/SnO2/C catalyst retained 96%of its electrochemical surface area.
文摘An extended-gate field effect transistor (EGFET)of SnO_2/ITO glass was applied to manufacture the vitamin C sensor.Therefore,we immobilized the ascorbate oxidase with 3-glycidoxypropyltrimethoxysilane (GPTS)method to measure the different concentrations of the vitamin C solution in an optimum measurement environment.In order to find the best measurement conditions of the biosensor,we studied the vitamin C sensor in different pH values of the phosphate buffer solution (PBS).Additionally,we used experimental results to discuss the response time and response voltage to compare vitamin C with orange juice for the vitamin C sensor.
