An in-situ reflection ultramicroelectrode microscopic FTIR spectroelectrochemical cell was constructed and demonstrated by using hexacyanoferrate redox couple in aqueous sulphate solution.An excellent microscopic SNIF...An in-situ reflection ultramicroelectrode microscopic FTIR spectroelectrochemical cell was constructed and demonstrated by using hexacyanoferrate redox couple in aqueous sulphate solution.An excellent microscopic SNIFTIRS reflection spectra had been obtained with no difficulty of IR beam focusing.The cell is simple in construction and convenient for use,And it will have most of all advantages of micro-/ultramicroelectrode.展开更多
In this work, the wafer bowing during growth can be in-situ measured by a reflectivity mapping method in the 3×2 Thomas Swan close coupled showerhead metal organic chemical vapor deposition（MOCVD） system. The r...In this work, the wafer bowing during growth can be in-situ measured by a reflectivity mapping method in the 3×2 Thomas Swan close coupled showerhead metal organic chemical vapor deposition（MOCVD） system. The reflectivity mapping method is usually used to measure the film thickness and growth rate. The wafer bowing caused by stresses（tensile and compressive） during the epitaxial growth leads to a temperature variation at different positions on the wafer, and the lower growth temperature leads to a faster growth rate and vice versa. Therefore, the wafer bowing can be measured by analyzing the discrepancy of growth rates at different positions on the wafer. Furthermore, the wafer bowings were confirmed by the ex-situ wafer bowing measurement. High-resistivity and low-resistivity Si substrates were used for epitaxial growth. In comparison with low-resistivity Si substrate, Ga N grown on high-resistivity substrate shows a larger wafer bowing caused by the highly compressive stress introduced by compositionally graded Al Ga N buffer layer. This transition of wafer bowing can be clearly in-situ measured by using the reflectivity mapping method.展开更多
Electrical double-layer capacitors(EDLCs)consist of energy storage devices that present high-power and moderate energy density.The electrolyte and electrode physicochemical properties are crucial for improving their o...Electrical double-layer capacitors(EDLCs)consist of energy storage devices that present high-power and moderate energy density.The electrolyte and electrode physicochemical properties are crucial for improving their overall energy storage capabilities.Therefore,the stability of the EDLCs’materials is the primary focus of this study.Since energy storage depends on the specific capacitance,and also on the square of the maximum capacitive cell voltage(UMCV).Thus,electrodes with high specific surface area(SSA)and electrolytes with excellent electrochemical stability are commonly reported in the literature.Aqueous electrolytes are safer and green devices compared to other organic-based solutions.On the other hand,their UMCVis reduced compared to other electrolytes(e.g.,organic-based and ionic liquids).In this sense,spanning the UMCVfor aqueous-based electrolytes is a’hot topic’research.Unfortunately,the lack of protocols to establish reliable UMCVvalues has culminated in the publishing of several conflicting results.Herein,we confirm that multiwalled carbon nanotubes(MWCNTs)housed in cells degrade and produce CO_(2) under abusive polarisation conditions.It is probed by employing electrochemical techniques,in-situ FTIR and in-situ Raman spectroscopies.From these considerations,the current study uses spectro-electrochemical techniques to support the correct determination of the electrode and electrolyte stability conditions as a function of the operating electrochemical parameters.展开更多
An in-situ optically transparent thin-layer microscopic FTIR spectroelectro- chemical cell was constructed.Using this cell,we characterize a concentration-distance profile in the electrochemical diffusion thin-layer b...An in-situ optically transparent thin-layer microscopic FTIR spectroelectro- chemical cell was constructed.Using this cell,we characterize a concentration-distance profile in the electrochemical diffusion thin-layer by in-situ adjusting the focal point at different distances to the electrode surface.展开更多
Redox mechanism of ferrocene, acetylferrocene, ferrocenyl cinnamenyl ketone at a platinum electrode was studied with cyclic voltammetry (CV) and in-situ Fourier transform infrared (FTIR) spectroelectrochemistry. The ...Redox mechanism of ferrocene, acetylferrocene, ferrocenyl cinnamenyl ketone at a platinum electrode was studied with cyclic voltammetry (CV) and in-situ Fourier transform infrared (FTIR) spectroelectrochemistry. The IR bands in the range of 2000-1000 cm-1 attributed to the stretching and ring vibrations of these materials show the main spectral changes in the processes.展开更多
文摘An in-situ reflection ultramicroelectrode microscopic FTIR spectroelectrochemical cell was constructed and demonstrated by using hexacyanoferrate redox couple in aqueous sulphate solution.An excellent microscopic SNIFTIRS reflection spectra had been obtained with no difficulty of IR beam focusing.The cell is simple in construction and convenient for use,And it will have most of all advantages of micro-/ultramicroelectrode.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61274039 and 51177175)the National Basic Research Program of China(Grant No.2011CB301903)+5 种基金the Ph.D.Programs Foundation of Ministry of Education of China(Grant No.20110171110021)the International Science and Technology Collaboration Program of China(Grant No.2012DFG52260)the International Science and Technology Collaboration Program of Guangdong Province,China(Grant No.2013B051000041)the Science and Technology Plan of Guangdong Province,China(Grant No.2013B010401013)the National High Technology Research and Development Program of China(Grant No.2014AA032606)the Opened Fund of the State Key Laboratory on Integrated Optoelectronics,China(Grant No.IOSKL2014KF17)
文摘In this work, the wafer bowing during growth can be in-situ measured by a reflectivity mapping method in the 3×2 Thomas Swan close coupled showerhead metal organic chemical vapor deposition（MOCVD） system. The reflectivity mapping method is usually used to measure the film thickness and growth rate. The wafer bowing caused by stresses（tensile and compressive） during the epitaxial growth leads to a temperature variation at different positions on the wafer, and the lower growth temperature leads to a faster growth rate and vice versa. Therefore, the wafer bowing can be measured by analyzing the discrepancy of growth rates at different positions on the wafer. Furthermore, the wafer bowings were confirmed by the ex-situ wafer bowing measurement. High-resistivity and low-resistivity Si substrates were used for epitaxial growth. In comparison with low-resistivity Si substrate, Ga N grown on high-resistivity substrate shows a larger wafer bowing caused by the highly compressive stress introduced by compositionally graded Al Ga N buffer layer. This transition of wafer bowing can be clearly in-situ measured by using the reflectivity mapping method.
基金the financial support from the Brazilian funding agencies CNPq(301486/2016-6)FAEPEX(2426/17)+7 种基金FAPESP(2020/04431-0,2020/04281-8,2016/25082-8,2017/11986-5,2017/11958-1,2014/02163-7,2018/20756-6,2018/02713-8)CAPES(1740195)the financial support from CNPq(Processes 131234/2020-0 and 130741/2021-3)the Fundação ao AmparoàPesquisa do Estado de Minas Gerais(FAPEMIGCNPq for the PQ-2 grant(Process 310544/20190)the support of Shell,the strategic importance of the support given by Brazil’s National Oil,Natural Gas,and Biofuels Agency(ANP)through the R&D levy regulationthe Center for Innovation on New Energies(CINE)the LNLS/CNPEM。
文摘Electrical double-layer capacitors(EDLCs)consist of energy storage devices that present high-power and moderate energy density.The electrolyte and electrode physicochemical properties are crucial for improving their overall energy storage capabilities.Therefore,the stability of the EDLCs’materials is the primary focus of this study.Since energy storage depends on the specific capacitance,and also on the square of the maximum capacitive cell voltage(UMCV).Thus,electrodes with high specific surface area(SSA)and electrolytes with excellent electrochemical stability are commonly reported in the literature.Aqueous electrolytes are safer and green devices compared to other organic-based solutions.On the other hand,their UMCVis reduced compared to other electrolytes(e.g.,organic-based and ionic liquids).In this sense,spanning the UMCVfor aqueous-based electrolytes is a’hot topic’research.Unfortunately,the lack of protocols to establish reliable UMCVvalues has culminated in the publishing of several conflicting results.Herein,we confirm that multiwalled carbon nanotubes(MWCNTs)housed in cells degrade and produce CO_(2) under abusive polarisation conditions.It is probed by employing electrochemical techniques,in-situ FTIR and in-situ Raman spectroscopies.From these considerations,the current study uses spectro-electrochemical techniques to support the correct determination of the electrode and electrolyte stability conditions as a function of the operating electrochemical parameters.
文摘An in-situ optically transparent thin-layer microscopic FTIR spectroelectro- chemical cell was constructed.Using this cell,we characterize a concentration-distance profile in the electrochemical diffusion thin-layer by in-situ adjusting the focal point at different distances to the electrode surface.
文摘Redox mechanism of ferrocene, acetylferrocene, ferrocenyl cinnamenyl ketone at a platinum electrode was studied with cyclic voltammetry (CV) and in-situ Fourier transform infrared (FTIR) spectroelectrochemistry. The IR bands in the range of 2000-1000 cm-1 attributed to the stretching and ring vibrations of these materials show the main spectral changes in the processes.
