0000000000009835
AUTHOR
Keddam M
Graphical Analysis of Electrochemical Impedance Spectroscopy of Two Consecutive Irreversible Electron Transfers. 1. Theoretical Study of the Anodic Dissolution of Metals
A general function for the faradaic impedance associated to a two consecutive single electron transfer mechanism followed by a irreversible first-order step has been obtained on the basis of formal kinetics. Kinetic parameters associated to this reaction mechanism can be obtained from the different kind of plots of the impedance function: Nyquist, Cole-Cole, and different Bode plots. A strategy for obtaining all parameters is suggested and analyzed on a detailed flowchart.
Graphical analysis of electrochemical impedance spectroscopy of two consecutive irreversible electron transfers. 2. Zinc anodic dissolution in acid media.
The graphical analysis of the impedance plots is used in the study of the electrodic systems that take place through two consecutive single electron transfers. The zinc anodic dissolution is studied by using this procedure. The characteristic points easily allow us to explain and to simulate the impedance behavior of this electrodic system according to the steady-state potential and the roughness of the working electrode. The direct procedure for parametrical identification from the graphical analysis allows us to reduce the time needed for an impedance experiment. This graphical analysis is suggested for studying thin coated galvanized steels.