Relaxation of the Adsorption with Charge Transfer: The Iodide Ion Adsorption on a Platinum Electrode

Abstract

The relaxation of the iodide ion adsorption on platinum electrodes with smooth and developed surfaces is studied in the time range 10^–4to 10³s and frequency range 10^–3to 10⁵Hz. Mathematical models matching experimental data to within the experimental accuracy are designed. Most adsorption centers on platinum have relaxation times τ > 0.1 s. The fraction of adsorption centers with τ > 100 s increases on the electrode with the developed surface, and in the ranges t< 0.1 s and F> 2 Hz, characteristics of this electrode are almost completely defined by the surface porosity. It is discovered that the electrode surface becomes smoother, leading to a slow drift of characteristics with time.