USE OF CONFORMAL-MAPS TO MODEL THE VOLTAMMETRIC RESPONSE OF COLLECTOR GENERATOR DOUBLE-BAND ELECTRODES

The utility of coordinate transformation in electrochemical problems, specifically those associated with nonlinear diffusion at microelectrodes, is discussed. The use of the Schwarz-Christoffel transformation of space is shown to provide a simple route to an exact expression for the steady-state limiting current of a double-band electrode as a function of the width-to-gap ratio. Additionally, the transformation approach allows improved accuracy and decreased computation time of digital simulations, over those done in the traditional real-space coordinates. Experiments with chemically stable systems, ferrocene and 9,10-diphenylanthracene (DPA) in acetonitrile, provide verification of digital simulations of the double-band electrode response. Agreement is also found between simulations of chemical reactions accompanying electron transfer and experiments for the oxidation of DPA in the presence of pyridine in acetonitrile, a system that shows a pseudo-first-order rate constant of 100 s-1.