采用溶胶-凝胶法制备Ti/Sn O_2-F电极,进行全氟辛酸(PFOA)电氧化降解的研究,实验考察了F替代Sb掺杂、电流密度、初始pH值和支持电解质对PFOA降解效率的影响。结果表明,当F替代Sb掺杂Sn O_2,电流密度为20 m A/cm^2,初始pH值3.7,支持电解...采用溶胶-凝胶法制备Ti/Sn O_2-F电极,进行全氟辛酸(PFOA)电氧化降解的研究,实验考察了F替代Sb掺杂、电流密度、初始pH值和支持电解质对PFOA降解效率的影响。结果表明,当F替代Sb掺杂Sn O_2,电流密度为20 m A/cm^2,初始pH值3.7,支持电解质为NaClO_4时,电解30 min后PFOA的降解率达98%。采用液相色谱-质谱联用(HPLC-MS/MS)和离子色谱(IC)对PFOA降解产物进行分析,解析了PFOA电氧化降解的反应机理。展开更多
介绍了Ag基触点材料的发展历史以及Ag Sn O2材料的研究现状,分析了Ag Sn O2材料在当前工业化生产中所面临的问题。针对国内粉体制备工艺的不足以及Ag Sn O2材料加工性能不佳等难题,总结了不同加工工艺对材料性能的影响,提出了以优化加...介绍了Ag基触点材料的发展历史以及Ag Sn O2材料的研究现状,分析了Ag Sn O2材料在当前工业化生产中所面临的问题。针对国内粉体制备工艺的不足以及Ag Sn O2材料加工性能不佳等难题,总结了不同加工工艺对材料性能的影响,提出了以优化加工工艺为出发点,探讨利用有限元分析(FEM)寻求最优工艺参数的可能性,并通过有限元分析法解决Ag Sn O2加工的困难,为改善材料的综合性能提供指导。展开更多
采用固相烧结法制备了(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1-x)Sn_x)O_3(BCZTS)无铅压电陶瓷。研究了不同含量SnO_2(x=0,0.02,0.04,0.06,0.08)对BCZT无铅压电陶瓷相结构、压电性能、介电性能和铁电性能的影响,并利用XRD、SEM、准静态d3...采用固相烧结法制备了(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1-x)Sn_x)O_3(BCZTS)无铅压电陶瓷。研究了不同含量SnO_2(x=0,0.02,0.04,0.06,0.08)对BCZT无铅压电陶瓷相结构、压电性能、介电性能和铁电性能的影响,并利用XRD、SEM、准静态d33测试仪等表征样品。结果表明,所有样品均为单一钙钛矿结构。当掺杂x=0.02时,(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1-x)Sn_x)O_3无铅压电陶瓷材料的综合性能优异:d33=553 p C/N,kp=49%,εr^7474(1 k Hz),tanδ~1.5%(1k Hz),Pr=6.06μC/cm^2,Ec=2 k V/cm,利用Curie-Weiss定律对该实验结果进行拟合,发现x=0.02的样品的介电弛豫特征更为明显。展开更多
A series of TiO2-SnO2 nano-sized composite photo-catalysts containing Sn (9.3%-30.1%) were prepared from TiCI4 and SnCl4·5H2O by using sol-gel, supercritical fluid dry and solid-phase reaction (SCFD) combination ...A series of TiO2-SnO2 nano-sized composite photo-catalysts containing Sn (9.3%-30.1%) were prepared from TiCI4 and SnCl4·5H2O by using sol-gel, supercritical fluid dry and solid-phase reaction (SCFD) combination technology. Characterizations with X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR) showed that, in addition to anatase type TiO2, a new active phase (Ti, Sn)O2 (with particle size of 2.0-4.3 nm) formed, and there were no SnO2 crystals observed in the range of the doping concentration studied. Photo-catalytic reaction of phenol was used as a model reaction to evaluate the catalytic activities of the obtained catalysts. Compared with pure TiO2 or Ti-Sn catalyst prepared with general sol-gel method, Ti-Sn nano-composite photo-catalyst thus obtained showed significant improvement in catalytic activity. The photo-catalytic degradation rate of phenol could reach as high as 93.5% after 7 h. The preparation conditions of the new phase (Ti, Sn)O2 were investigated and its catalytic mechanism was proposed. The photo-catalytic particles prepared using SCFD combination technology exhibited small particle size, large surface area and high activity.展开更多
The electrode materials SnO2, RuO2 and (Sn-Ru)O2 were synthesized through precipitation method from SnCl2·2H2O and RuCl2·2H2O solutions. The obtained nano-sized pristine products were characterized using X-r...The electrode materials SnO2, RuO2 and (Sn-Ru)O2 were synthesized through precipitation method from SnCl2·2H2O and RuCl2·2H2O solutions. The obtained nano-sized pristine products were characterized using X-ray diffractometry, Scanning Electron Microscopy (SEM), differential scanning calorimetry (DSC)-thermogravimetric analysis (TGA) and cyclic voltammetry (CV). The Debye–Scherrer formula was used to estimate the average size of the nanoparticles SnO2 (36 nm), RuO2(24 nm), and (Sn-Ru)O2 (19 nm). Electrochemical studies were carried out to examine the capacitance of SnO2, RuO2, (Sn-Ru)O2 electrodes in 0.5 M H2SO4 at various scan rates. The estimated electrode capacitance was de-termined to decrease with an increase of scan rate.展开更多
The first-principles calculations are performed to investigate the adsorption of O2 molecules on an Sn（lll） 2 × 2 surface. The chemisorbed adsorption precursor states for O2 are identified to be along the paral...The first-principles calculations are performed to investigate the adsorption of O2 molecules on an Sn（lll） 2 × 2 surface. The chemisorbed adsorption precursor states for O2 are identified to be along the parallel and vertical channels, and the surface reconstructions of Sn（111） induced by oxygen adsorption are studied. Based on this, the adsorption behaviours of O2 on X（111） （X=Si, Ge, Sn, Pb） surfaces are analysed, and the most stable adsorption channels of O2 on X（111） （X=Si, Ge, Sn, Pb） are identified. The surface reconstructions and electron distributions along the most stable adsorption channels are discussed and compared. The results show that the O2 adsorption ability declines gradually and the amount of charge transferred decreases with the enhancement of metallicity.展开更多
Electrocatalytic nitrate reduction reaction(NO_(3)−RR)and its coupling with CO_(2)could provide new sustainable pathways for the synthesis of ammonia and urea,respectively.However,their practical applications are hind...Electrocatalytic nitrate reduction reaction(NO_(3)−RR)and its coupling with CO_(2)could provide new sustainable pathways for the synthesis of ammonia and urea,respectively.However,their practical applications are hindered by the lack of catalysts with satisfied Faraday efficiency and yield.Herein,we report self-supported electrochemically reconstituted Sn/Cu_(2)O bifunctional catalysts for the efficient synthesis of ammonia and urea.In the NO_(3)−RR,Sn/Cu_(2)O-βcatalysts electrodeposited for 800 s provided an excellent ammonia yield of 0.496 mmol·h(−1)·cm^(−2)and Faraday efficiency of 98.5%.Besides,Sn/Cu_(2)O-αcatalysts electrodeposited for 400 s achieved the maximum Faraday efficiency of 13.5%and outstanding urea yield of 32.35μmol·h^(−1)·cm^(−2)in C-N coupling.Comprehensive analyses confirm that bi-selectivity to ammonia and urea synthesis could be achieved by modulating the chemical state of Cu in Sn/Cu_(2)O catalysts,these results are superior to most reported transition metal-based catalysts in synthesis of urea and/or ammonia.In situ Fourier transform infrared(FTIR)spectroscopy revealed that^(*)CONH_(2)intermediates are essential for urea synthesis.This work will provide a feasible strategy for the development of bifunctional electrocatalysts for efficient ammonia and urea synthesis.展开更多
文摘介绍了Ag基触点材料的发展历史以及Ag Sn O2材料的研究现状,分析了Ag Sn O2材料在当前工业化生产中所面临的问题。针对国内粉体制备工艺的不足以及Ag Sn O2材料加工性能不佳等难题,总结了不同加工工艺对材料性能的影响,提出了以优化加工工艺为出发点,探讨利用有限元分析(FEM)寻求最优工艺参数的可能性,并通过有限元分析法解决Ag Sn O2加工的困难,为改善材料的综合性能提供指导。
文摘采用固相烧结法制备了(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1-x)Sn_x)O_3(BCZTS)无铅压电陶瓷。研究了不同含量SnO_2(x=0,0.02,0.04,0.06,0.08)对BCZT无铅压电陶瓷相结构、压电性能、介电性能和铁电性能的影响,并利用XRD、SEM、准静态d33测试仪等表征样品。结果表明,所有样品均为单一钙钛矿结构。当掺杂x=0.02时,(Ba_(0.85)Ca_(0.15))(Ti_(0.9)Zr_(0.1-x)Sn_x)O_3无铅压电陶瓷材料的综合性能优异:d33=553 p C/N,kp=49%,εr^7474(1 k Hz),tanδ~1.5%(1k Hz),Pr=6.06μC/cm^2,Ec=2 k V/cm,利用Curie-Weiss定律对该实验结果进行拟合,发现x=0.02的样品的介电弛豫特征更为明显。
基金The authors thank the National Natural Scir nce Foun-dation of China(No.20076004)the National Development Project of High Technology(No.2001AA322030)the Doctoral Program of Higher Education(No.2000001005)for the financial support of this project.
文摘A series of TiO2-SnO2 nano-sized composite photo-catalysts containing Sn (9.3%-30.1%) were prepared from TiCI4 and SnCl4·5H2O by using sol-gel, supercritical fluid dry and solid-phase reaction (SCFD) combination technology. Characterizations with X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR) showed that, in addition to anatase type TiO2, a new active phase (Ti, Sn)O2 (with particle size of 2.0-4.3 nm) formed, and there were no SnO2 crystals observed in the range of the doping concentration studied. Photo-catalytic reaction of phenol was used as a model reaction to evaluate the catalytic activities of the obtained catalysts. Compared with pure TiO2 or Ti-Sn catalyst prepared with general sol-gel method, Ti-Sn nano-composite photo-catalyst thus obtained showed significant improvement in catalytic activity. The photo-catalytic degradation rate of phenol could reach as high as 93.5% after 7 h. The preparation conditions of the new phase (Ti, Sn)O2 were investigated and its catalytic mechanism was proposed. The photo-catalytic particles prepared using SCFD combination technology exhibited small particle size, large surface area and high activity.
文摘The electrode materials SnO2, RuO2 and (Sn-Ru)O2 were synthesized through precipitation method from SnCl2·2H2O and RuCl2·2H2O solutions. The obtained nano-sized pristine products were characterized using X-ray diffractometry, Scanning Electron Microscopy (SEM), differential scanning calorimetry (DSC)-thermogravimetric analysis (TGA) and cyclic voltammetry (CV). The Debye–Scherrer formula was used to estimate the average size of the nanoparticles SnO2 (36 nm), RuO2(24 nm), and (Sn-Ru)O2 (19 nm). Electrochemical studies were carried out to examine the capacitance of SnO2, RuO2, (Sn-Ru)O2 electrodes in 0.5 M H2SO4 at various scan rates. The estimated electrode capacitance was de-termined to decrease with an increase of scan rate.
基金Project supported by the National Natural Science Foundation of China(Grant No.51102009)the Fundamental Research Funds for the Central Universities,China(Grant No.JD1109)
文摘The first-principles calculations are performed to investigate the adsorption of O2 molecules on an Sn（lll） 2 × 2 surface. The chemisorbed adsorption precursor states for O2 are identified to be along the parallel and vertical channels, and the surface reconstructions of Sn（111） induced by oxygen adsorption are studied. Based on this, the adsorption behaviours of O2 on X（111） （X=Si, Ge, Sn, Pb） surfaces are analysed, and the most stable adsorption channels of O2 on X（111） （X=Si, Ge, Sn, Pb） are identified. The surface reconstructions and electron distributions along the most stable adsorption channels are discussed and compared. The results show that the O2 adsorption ability declines gradually and the amount of charge transferred decreases with the enhancement of metallicity.
基金supported by the Key Projects of Intergovernmental International Cooperation in Key R&D Programs of the Ministry of Science and Technology of China(No.2021YFE0115800)the National Science Funding Committee of China(No.U20A20250)+1 种基金the Programs of the Science and Technology of Yulin City(No.CXY-2023-ZX04)the funding support from Shccig-Qinling Program.
文摘Electrocatalytic nitrate reduction reaction(NO_(3)−RR)and its coupling with CO_(2)could provide new sustainable pathways for the synthesis of ammonia and urea,respectively.However,their practical applications are hindered by the lack of catalysts with satisfied Faraday efficiency and yield.Herein,we report self-supported electrochemically reconstituted Sn/Cu_(2)O bifunctional catalysts for the efficient synthesis of ammonia and urea.In the NO_(3)−RR,Sn/Cu_(2)O-βcatalysts electrodeposited for 800 s provided an excellent ammonia yield of 0.496 mmol·h(−1)·cm^(−2)and Faraday efficiency of 98.5%.Besides,Sn/Cu_(2)O-αcatalysts electrodeposited for 400 s achieved the maximum Faraday efficiency of 13.5%and outstanding urea yield of 32.35μmol·h^(−1)·cm^(−2)in C-N coupling.Comprehensive analyses confirm that bi-selectivity to ammonia and urea synthesis could be achieved by modulating the chemical state of Cu in Sn/Cu_(2)O catalysts,these results are superior to most reported transition metal-based catalysts in synthesis of urea and/or ammonia.In situ Fourier transform infrared(FTIR)spectroscopy revealed that^(*)CONH_(2)intermediates are essential for urea synthesis.This work will provide a feasible strategy for the development of bifunctional electrocatalysts for efficient ammonia and urea synthesis.
