X-ray photoelectron spectroscopic study of the film formed on a gold electrode during the electrochemical reduction of chromium(VI)

Abstract

The presence and nature of the film produced on a gold electrode by polarisation in 1.0 mol dm^–3 chromic acid and 1.0 mol dm^–3 chromic acid + 0.01 mol dm^–3 sulphuric acid solutions, over a wide range of electrode potentials has been demonstrated by X-ray photoelectron spectroscopy. The relative amounts of the different species present has been determined over this wide potential range for both of these solutions.

A study of the intensities of the photoelectron peaks demonstrates how the spectroscopic data may be correlated with electrochemical measurements and how they may be combined to determine the film thickness. The partial ionic charge of the chromium ion has been calculated for a series of chromium compounds, so that the partial ionic charge of the electrode species may be estimated by comparison.