Model of inner part of electrical double layer on a recharged electrode surface

Abstract

The specific adsorption of various anions has been studied on the bismuth electrode in the aqueous and ethanolic solutions of mixed electrolytes with constant ionic strength by measuring the potential dependence of differential capacity of bismuth. The charge due to specifically adsorbed anions was calculated by the Hurwitz-Dutkiewicz-Parsons method. Assuming the entrance of cations into the inner part of the double layer on the bismuth electrode, recharged by the specifically adsorbed anions, the charge due to the cations in the inner layer, the corrected values of the outer Helmholtz plane potential and of the potential drop across the inner layer have been calculated. A simple model of the inner layer in presence of ionic associates is developed. The main parameters characterizing the specific adsorption of ions and the structure of the inner layer have been calculated. A procedure has been developed for the calculation of the charge due to the cations in the inner layer by the dependence on the electrode potential on the charge of specifically adsorbed anions.