Calculation of reversible cyclic voltammograms at spherical electrodes

Abstract

Cyclic voltammetry is customarily carried out at stationary spherical mercury electrodes, whereas available theory is largely based on planar diffusion. There are significant discrepancies between cyclic voltammograms obtained at spherical and planar electrodes, especially for experiments of long duration, when the reduced species dissolves in the mercury or when the diffusion coefficients are markedly unequal. This article presents a partly analytical formula for predicting the cyclovoltammetric current at a reversible spherical electrode under conditions of mild sphericity. Predictions are then made of the shapes of typical cyclic voltammograms and these are compared with experiment.