Analytical approach to the transient and steady-state Cyclic Voltammetry of non-reversible electrode processes. Defining the transition from macro to microelectrodes

摘要

An explicit analytical easily programmable expression for the current-potential curves of electrode processes of any degree of reversibility in Cyclic Voltammetry (CV), valid for small spherical electrodes, is presented. From this solution a complete analysis of the most relevant parameters of the CV curves in terms of the electrode size and the scan rate is made, and the different influences of the kinetics of the electrode process clearly determined. Moreover, the evolution of the main characteristics of the voltammograms in the transition from macro- to micro-electrodes is described. A global expression for the rate constant collecting the influence of the kinetics in the complete range of electrode size from macro to nanoelectrodes is defined. Simple particular expressions covering different kinetic and geometric limits are presented. Methods for extracting kinetic parameters of the response are proposed. (C) 2016 Elsevier Ltd. All rights reserved.