Title: Voltammetry：principles and practice
Speaker: Prof. Jingyuan Chen, Fukui University, Japan
Date: 2019-04-01 09:00-11:30 AM
Location: Room 112, Chemistry Building
Abstract：
Theories of cyclic voltammetry, ac-impedance techniques and the double layer capacitive currents are described concisely to touch their principles. Applications of the theory to experimental data do not always lead to reasonable interpretation consistent with by other techniques. Several tips are presented not only in the experimental viewpoint but also in a perspective of the data analysis. Most of them are devoted to cyclic voltammetry. They include shape of voltammograms, peak currents and peak potentials, diffusion- and adsorption-controls, the number of electrons, reference and counter electrodes, usage of ac-impedance, heterogeneous charge transfer rates, and combination with data by scanning probe microscope. They belong partially to recommendation and partially prohibition.
The simplest theories for voltammetry are limited to the rate-determining steps of diffusion of redox species and reactions of adsorbed species without interaction. Variation of scan rates as well as a reverse potential can predict reacting species and reaction mechanisms. Furthermore, the following viewpoints are helpful for interpreting mechanisms:
(a) comparison of values of experimental peak currents with theoretical ones, instead of discussingDEpand E1/2;
(b) examining the proportionality of Ip vs. v or vs. v1/2, i.e., values of the intercept of the linearity;
(c) possibility of a source of contamination in solution a reference electrode and a counter electrode;
(d) attention to very slow relaxation of DL capacitive currents.
Biography:
Dr. Jingyuan Chen is work as a professor at Department of Applied Physics, University of Fukui. Her research is directed to fundamentals of electrochemistry with theoretical backgrounds. She was supervised by Prof. Koichi J. Aoki at University of Fukui, and was awarded a Ph.D. She worked as a lecturer at Faculty of Science, Kanazawa University, and then worked as a visitor scholar at Henry S. White laboratory. Then, she moved to University of Fukui in 2002. She is a member of many professional societies, such as ACS.Until now, she has published hundreds of peer-reviewed publications in international journals and several patents.
