Studies of the electrical double layer and of adsorbed species on electrodes using modulated specular reflectance spectroscopy

The optical properties of adsorbed hydrogen on a platinum cathode have been studied. The results are interpreted in terms of r and s-adatom formation for the two types of adsorption. The reflectivity change in the double layer region of potential is ascribed to an electroreflectance contribution from the metal. Studies of the simple double layer formed between KF solution and a lead or mercury electrode show that the reflectivity changes caused by the diffuse double layer are small compared with contributions from the compressed water in the inner layer and from the electroreflectance effect.