Photoelectrochemically induced periodical deposition patterns of platinum on p-InP. Part 2: kinetic model

Abstract

A kinetic model is presented which rationalizes the previous observation of spatially periodical platinum deposition induced photocathodically by a moving laser spot on p-InP. The model is similar to that of the Liesegang phenomenon. It includes the following processes: nucleation of ad-atoms, growth of nuclei, formation of a depletion zone, limitation of mass transport by diffusion, shift of the photocathodic reaction zone along with the moving laser spot. Computer simulations of the model equations reproduce the experimentally found periodical platinum deposition and demonstrate the spatiotemporal evolution of the number of nuclei, the deposition peaks and the corresponding hexachloroplatinate(IV) concentration profile. The influence of the model parameters is discussed.