Electrochemical oxygen reduction reaction(ORR)is crucial for fuel cells and metal-air batteries,while the oxygen consumption dynamics study during ORR,which affects the ORR efficiency,is not as concerned as catalysts ...Electrochemical oxygen reduction reaction(ORR)is crucial for fuel cells and metal-air batteries,while the oxygen consumption dynamics study during ORR,which affects the ORR efficiency,is not as concerned as catalysts design does.Herein the consumption behavior of an individual oxygen bubble on Pt foils with different wettabilities during ORR was tracked by a real-time approach to reveal whether the surface wettability of electrode can influence the consumption dynamics and determine the reaction reactive zones of oxygen bubble consumption.The oxygen bubble underwent a "constant contact angle"dominant consumption model on aerophobic Pt foil,while an initial "constant radius"and the subsequent"constant contact angle"oxygen consumption models were observed on aero philic Pt foil.Results here demonstrated that the current was proportional to the bottom contact area,rather than the three-phase contact line of the bubbles according to the fitting curves between individual bubble current and the consumption behavior parameters.This study highlights the important role of the gas-solid interface in influencing the efficiency of gas consumption electrochemical reactions,which shall benefit the understanding of reaction kinetics and the rational design of electrocatalysts.展开更多
本文结合电化学方法与原子力显微镜力曲线技术,研究了两种烷基侧链长度不同的离子液体BMITFSA和OMITFSA在Au(111)电极表面附近的层状结构的数目和耐受力对电位的依赖性,探究了烷基侧链长度变化对界面层状结构的影响.研究表明,不同烷基...本文结合电化学方法与原子力显微镜力曲线技术,研究了两种烷基侧链长度不同的离子液体BMITFSA和OMITFSA在Au(111)电极表面附近的层状结构的数目和耐受力对电位的依赖性,探究了烷基侧链长度变化对界面层状结构的影响.研究表明,不同烷基侧链长度的离子液体体系力-电位曲线形状基本相似.在零电荷电位(the potential of zero charge,PZC)附近时,力值最小,因为此时电极表面荷电量较小,层状结构不稳定;电位偏离PZC的过程中,第一层层状结构力值呈现先增大后减小的趋势.受到烷基侧链所处的不同位置影响,在PZC电位以负,短侧链离子液体的层状结构稳定性较好,而PZC电位以正,长侧链离子液体的稳定性较好.展开更多
Chemical growth process that favours deposition of semiconductor materials from a liquid phase was used to obtain CdS and HgxCd1-xS(0≤x≤0.25)photosensitive thin film electrodes on the stainless steel substrates.The... Chemical growth process that favours deposition of semiconductor materials from a liquid phase was used to obtain CdS and HgxCd1-xS(0≤x≤0.25)photosensitive thin film electrodes on the stainless steel substrates.The deposition of these series of thin films was carried out under the optimized conditions of temperature(60℃),time(90 min)and pH(10.8±0.2).These films were then employed as photosensitive electrode in an electrochemical photosensing cell consisting of sulphide/polysulphide redox electrolyte and a graphite counter electrode.The cells were illuminated by an input illumination intensity of 13 mW/cm 2 and the cell characteristic parameters namely photocurrent(Iph),photo voltage(Vph),the quantum conversion efficiency(η%)and fill factor(ff %)have been determined.Both Vph and Iph have been found to be boosted as the electrode composition is altered.The conversion efficiency and fill factor enhanced from 0.52%to 1.30%and 31.8%to 37.8%,respectively for the change of electrode composition from 0 to 0.08.Determination of junction ideality factor(nd)showed recombination mechanism at the electrode-electrolyte interface.Barrier height measurements gave Pool-Frenkel type conduction mechanism.The flat band potentials(Vfb)were determined for all the cells and found to be enhanced with x up to 0.08 and then decreased for further increase in x.The lighted junction quality factor(nL)is increased from 1.49 to 2.94 as the photoelectrode composition(x)was varied from 0 to 0.08.The barrier heights(B)at the electrode/electrolyte interfaces were also determined.It is found that B is higher for a cell of electrode composition equal to 0.08.The spectral studies on these cells showed the cut off wavelength(λc)shifted from 530 nm to 800 nm.The transient response studies showed presence of surface states at the interface that causes Fermi-level pinning.Overall,performance of the electrochemical photosensing cell is found to be improved after Hg-corboration in CdS and is optimum at x= 0.08.展开更多
This paper studies the effects of deflection on the SiO2 barrier layer and molybdenum(Mo)back electrode of Cu(In,Ga)Se2 thin-film solar cells,prepared via magnetron sputtering on type SUS431 stainless steel substrate... This paper studies the effects of deflection on the SiO2 barrier layer and molybdenum(Mo)back electrode of Cu(In,Ga)Se2 thin-film solar cells,prepared via magnetron sputtering on type SUS431 stainless steel substrates.The surface micro-cracks and sheet resistance of thin films had been observed and measured for in-situ bend tests.Experimental results show that increasing the thickness of the SiOx barrier has a better property to prevent cracks induced by bending stress.The sheet resistance of a Mo film increases alongside the bending of the curvature radius.The maximum allowed value of the curvature radius of the SiOx barrier layer,molybdenum electrodes,and the thin film CIGS absorbing layer should be 16 mm,20 mm,and 26 mm,respectively.Therefore,the maximum curvature radius limit should be 26 mm or less for CIGS thin-film solar cells prepared via sputtering on type SUS431 stainless steel substrates.展开更多
基金the National Natural Science Foundation of China(Nos.21675007,21676015,21520102002,91622116)the National Key Research and Development Project of China(Nos.2018YFB1502401,2018YFA0702002),the Royal Society and the Newton Fund Through the Newton Advanced Fellowship Award(No.NAF/R1/191294)+2 种基金the Program for Changjiang Scholars and Innovation Research Team in the University,China(No.IRT1205)Fundamental Research Funds for the Central Universities of Chinathe Long-term Subsidy Mechanism from the Ministry of Finance and the Ministry of Education of China。
文摘Electrochemical oxygen reduction reaction(ORR)is crucial for fuel cells and metal-air batteries,while the oxygen consumption dynamics study during ORR,which affects the ORR efficiency,is not as concerned as catalysts design does.Herein the consumption behavior of an individual oxygen bubble on Pt foils with different wettabilities during ORR was tracked by a real-time approach to reveal whether the surface wettability of electrode can influence the consumption dynamics and determine the reaction reactive zones of oxygen bubble consumption.The oxygen bubble underwent a "constant contact angle"dominant consumption model on aerophobic Pt foil,while an initial "constant radius"and the subsequent"constant contact angle"oxygen consumption models were observed on aero philic Pt foil.Results here demonstrated that the current was proportional to the bottom contact area,rather than the three-phase contact line of the bubbles according to the fitting curves between individual bubble current and the consumption behavior parameters.This study highlights the important role of the gas-solid interface in influencing the efficiency of gas consumption electrochemical reactions,which shall benefit the understanding of reaction kinetics and the rational design of electrocatalysts.
文摘本文结合电化学方法与原子力显微镜力曲线技术,研究了两种烷基侧链长度不同的离子液体BMITFSA和OMITFSA在Au(111)电极表面附近的层状结构的数目和耐受力对电位的依赖性,探究了烷基侧链长度变化对界面层状结构的影响.研究表明,不同烷基侧链长度的离子液体体系力-电位曲线形状基本相似.在零电荷电位(the potential of zero charge,PZC)附近时,力值最小,因为此时电极表面荷电量较小,层状结构不稳定;电位偏离PZC的过程中,第一层层状结构力值呈现先增大后减小的趋势.受到烷基侧链所处的不同位置影响,在PZC电位以负,短侧链离子液体的层状结构稳定性较好,而PZC电位以正,长侧链离子液体的稳定性较好.
文摘 Chemical growth process that favours deposition of semiconductor materials from a liquid phase was used to obtain CdS and HgxCd1-xS(0≤x≤0.25)photosensitive thin film electrodes on the stainless steel substrates.The deposition of these series of thin films was carried out under the optimized conditions of temperature(60℃),time(90 min)and pH(10.8±0.2).These films were then employed as photosensitive electrode in an electrochemical photosensing cell consisting of sulphide/polysulphide redox electrolyte and a graphite counter electrode.The cells were illuminated by an input illumination intensity of 13 mW/cm 2 and the cell characteristic parameters namely photocurrent(Iph),photo voltage(Vph),the quantum conversion efficiency(η%)and fill factor(ff %)have been determined.Both Vph and Iph have been found to be boosted as the electrode composition is altered.The conversion efficiency and fill factor enhanced from 0.52%to 1.30%and 31.8%to 37.8%,respectively for the change of electrode composition from 0 to 0.08.Determination of junction ideality factor(nd)showed recombination mechanism at the electrode-electrolyte interface.Barrier height measurements gave Pool-Frenkel type conduction mechanism.The flat band potentials(Vfb)were determined for all the cells and found to be enhanced with x up to 0.08 and then decreased for further increase in x.The lighted junction quality factor(nL)is increased from 1.49 to 2.94 as the photoelectrode composition(x)was varied from 0 to 0.08.The barrier heights(B)at the electrode/electrolyte interfaces were also determined.It is found that B is higher for a cell of electrode composition equal to 0.08.The spectral studies on these cells showed the cut off wavelength(λc)shifted from 530 nm to 800 nm.The transient response studies showed presence of surface states at the interface that causes Fermi-level pinning.Overall,performance of the electrochemical photosensing cell is found to be improved after Hg-corboration in CdS and is optimum at x= 0.08.
基金supported in part by the Materials and Electro-Optics Research Division,Chung-Shan Institute of Science and Technology and the National Science Council of Taiwan,R.O.C.under contract numbers CSIST-769-V204
文摘 This paper studies the effects of deflection on the SiO2 barrier layer and molybdenum(Mo)back electrode of Cu(In,Ga)Se2 thin-film solar cells,prepared via magnetron sputtering on type SUS431 stainless steel substrates.The surface micro-cracks and sheet resistance of thin films had been observed and measured for in-situ bend tests.Experimental results show that increasing the thickness of the SiOx barrier has a better property to prevent cracks induced by bending stress.The sheet resistance of a Mo film increases alongside the bending of the curvature radius.The maximum allowed value of the curvature radius of the SiOx barrier layer,molybdenum electrodes,and the thin film CIGS absorbing layer should be 16 mm,20 mm,and 26 mm,respectively.Therefore,the maximum curvature radius limit should be 26 mm or less for CIGS thin-film solar cells prepared via sputtering on type SUS431 stainless steel substrates.