ELECTROHYDRODYNAMIC IMPEDANCE - A TOOL FOR STUDYING ELECTRODE PROCESSES

The general question of the theoretical description and application of the hydroelectrochemical impedance has been considered. The problem can be broken down in a natural way into three steps: analysis of the hydrodynamic conditions (step I), analysis of the mass-transfer processes (step II), and inclusion of an equation of slow discharge (step III). The theory has been illustrated by applications in highly diverse areas of electrochemistry: electrocrystallization, the anodic dissolution of metals, corrosion processes, modified electrodes, passive layers, the determination of molecular diffusion coefficients, etc. The technique of using the hydroelectrochemical impedance as a perturbing force utilizes fluctuations or pulsations of the hydrodynamic velocity and, therefore, makes it possible to investigate electrochemical processes taking place at an electrodelsolution boundary under the conditions of weak electric perturbations.