The Experts below are selected from a list of 159 Experts worldwide ranked by ideXlab platform
Jason D Riley - One of the best experts on this subject based on the ideXlab platform.
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nonlinear analysis of a classical system the Faradaic Process
Electrochimica Acta, 2013Co-Authors: Ning Xu, Jason D RileyAbstract:Abstract Electrochemical impedance spectroscopy (EIS) is a well established technique and adopted in characterizing heterogeneous interface properties in various fields, such as batteries, fuel cells and corrosion. As an extension to traditional linear EIS technique, nonlinear EIS (NLEIS) is a developing technique that benefits from considerably higher resolution, better sensitivity in determining reaction mechanisms with no extra cost for hardware and measurement time. However, the fundamental concepts of harmonic impedance and optimal experimental as well as analysis procedure have yet to be fully developed. This paper explores the potential and some fundamental characteristics of NLEIS by revisiting one of the most stable and well understood electrochemical systems – the ferri–ferrocyanide redox couple. It was found that the inflections on odd harmonic curves follow a predictable trend, shifting towards lower frequency with increasing order. Even harmonics behave differently and contain critical information about the symmetry of the system. In contrast to EIS where the transfer coefficient is obtained by measurements on solutions of different concentrations, it is demonstrated that analysis of the even harmonics can yield the transfer coefficient for the reaction from measurements of a single solution.
Harry O Finklea - One of the best experts on this subject based on the ideXlab platform.
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second harmonic ac voltammetry study of a fast Faradaic Process in the presence of the uncompensated resistance
Journal of Electroanalytical Chemistry, 2000Co-Authors: Dmitri A Brevnov, Harry O FinkleaAbstract:Abstract A procedure is presented for the analysis of Faradaic admittance obtained by the second harmonic ac voltammetry in the presence of the uncompensated resistance. The procedure involves the analysis of the equivalent circuit with a current source at the double frequency and normalization of the second harmonic Faradaic current to the square of the interfacial potential. A system was developed for both instrument control and data acquisition in order to implement this method. The procedure was applied to an ac quasi-reversible (over the frequency range 100 Hz to 1 kHz) case for a freely diffusing redox species Ru(NH3)63+. The validity of the suggested method was established by comparison of the parameters derived from the first and second harmonic Faradaic admittance data.
Ning Xu - One of the best experts on this subject based on the ideXlab platform.
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nonlinear analysis of a classical system the Faradaic Process
Electrochimica Acta, 2013Co-Authors: Ning Xu, Jason D RileyAbstract:Abstract Electrochemical impedance spectroscopy (EIS) is a well established technique and adopted in characterizing heterogeneous interface properties in various fields, such as batteries, fuel cells and corrosion. As an extension to traditional linear EIS technique, nonlinear EIS (NLEIS) is a developing technique that benefits from considerably higher resolution, better sensitivity in determining reaction mechanisms with no extra cost for hardware and measurement time. However, the fundamental concepts of harmonic impedance and optimal experimental as well as analysis procedure have yet to be fully developed. This paper explores the potential and some fundamental characteristics of NLEIS by revisiting one of the most stable and well understood electrochemical systems – the ferri–ferrocyanide redox couple. It was found that the inflections on odd harmonic curves follow a predictable trend, shifting towards lower frequency with increasing order. Even harmonics behave differently and contain critical information about the symmetry of the system. In contrast to EIS where the transfer coefficient is obtained by measurements on solutions of different concentrations, it is demonstrated that analysis of the even harmonics can yield the transfer coefficient for the reaction from measurements of a single solution.
Nicholas Leventis - One of the best experts on this subject based on the ideXlab platform.
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steady state voltammetry with stationary disk millielectrodes in magnetic fields nonlinear dependence of the mass transfer limited current on the electron balance of the Faradaic Process
Journal of Physical Chemistry B, 1999Co-Authors: Nicholas LeventisAbstract:Generally, Faradaic current passing through an electrolytic cell placed in a magnetic field causes stirring of the electrolytic solution and current−voltage characteristics similar to those obtained with rotating disk electrodes. It is reported herein that the intensity of the hydrodynamic convection generated by conventional disk millielectrodes in magnetic fields is intimately related to the nature of the Faradaic Process, and that the mass-transfer limited current, il, is proportional to n3/2 where n is the number of electrons involved in the heterogeneous electron transfer. That finding has been justified on the basis of a feedback mechanism that relies on the dependence of the Faradaic current on the hydrodynamic velocity profile within the electrolytic conductor, and of the hydrodynamic velocity profile on the current. The implications of the nonlinear dependence of il on n have been discussed in terms of a moving-boundary diffusion-layer model which is introduced into digital simulations and reprod...
Dmitri A Brevnov - One of the best experts on this subject based on the ideXlab platform.
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second harmonic ac voltammetry study of a fast Faradaic Process in the presence of the uncompensated resistance
Journal of Electroanalytical Chemistry, 2000Co-Authors: Dmitri A Brevnov, Harry O FinkleaAbstract:Abstract A procedure is presented for the analysis of Faradaic admittance obtained by the second harmonic ac voltammetry in the presence of the uncompensated resistance. The procedure involves the analysis of the equivalent circuit with a current source at the double frequency and normalization of the second harmonic Faradaic current to the square of the interfacial potential. A system was developed for both instrument control and data acquisition in order to implement this method. The procedure was applied to an ac quasi-reversible (over the frequency range 100 Hz to 1 kHz) case for a freely diffusing redox species Ru(NH3)63+. The validity of the suggested method was established by comparison of the parameters derived from the first and second harmonic Faradaic admittance data.
