The Monte Carlo simulation of the voltammetry at fractal surfaces

Abstract

The single-sweep voltammetry of a reversible electrode reaction proceeding on a fractal metallic electrode was simulated by the Monte Carlo technique. The diffusion of oxidized and reduced forms was represented by two-dimensional movements in a plane perpendicular to the electrode surface. This model yields the theoretical current-voltage curve for a planar electrode and higher currents are observed at fractal surfaces. The simulations describe not only the macroscopic behaviour, but at the same time the stochastic properties of the electrode reactions. Schottky's theorem was confirmed for the planar electrode and the slope of Schottky's plot is almost doubled on a fractal surface. The distribution of reaction sites (or the penetration depth) was evaluated and can be used for more complex reaction schemes.