Reflectance studies of the gold/electrolyte interface

Abstract

The gold/electrolyte interface has been examined with both single and multiple reflection techniques. Gross errors arising from scattering have been identified with the latter using a large number of reflections. An explanation involving transitions of electrons in surface state (5d→ 6s) is proposed to account for the sensitivity of the reflectivity of gold electrodes to potential and to adsorbed ionic and neutral species. Previously proposed explanations involving changes in the Fermi level relative to non-surface electronic states appear untenable. A method is also proposed for examining the refractive index within the double layer if it is lower than that of the bulk solution.