Transient Current for a Rotating Disk Electrodes Produced by a Potential Step

Abstract

The non-steady state current of the rotating disk electrode for all time is presented in this manuscript for the first time. The model is based on the convection–diffusion equation with semi infinite boundary condition. The convection–diffusion equation is solved using the homotopy perturbation method, in conjunction with the Laplace transforms. Approximate analytical expressions for the concentration of the reactant and corresponding current for non-steady state conditions are derived. A two-point Padé approximant is proposed which is valid for entire time domain. The hitherto-known numerical and analytical solutions are compared with the present method.