查看文章

Chronocoulometry was employed to measure charge density at the Au(111) electrode surface. Thermodynamic analysis of the charge density data for ionic adsorption from a solution with an excess of a supporting electrolyte is described and used to study SO₄²⁻ adsorption at the Au(111) electrode from a 0.1 M HClO₄ solution. The Gibbs excesses determined from the charge density data are compared with the Gibbs excesses determined from radiochemical measurements using ³⁵S-labelled sulphate solutions. Very good agreement between the Gibbs excesses determined by the two techniques is observed.

Essin-Markov coefficients for SO₄²⁻ adsorption from two series of solutions were determined: (i) at constant pH and variable K₂SO₄ concentration; (ii) at constant K₂SO₄ concentration and variable pH. The Essin-Markov coefficients were used to identify the nature of the adsorbed species (HSO₄⁻ or SO₄² …