ADSORPTION STUDIES OF SOME INORGANIC AND ORGANIC SPECIES AT GOLD ELECTRODE/SOLUTION INTERFACES BY SPECULAR REFLECTION AND MAGNETO-OPTICAL ROTATION METHODS

Abstract

For application of the magneto-optical rotation (MOR) method to the determination of adsorption at electrode/solution interfaces, the adsorption of adenine and FMN, and Pb adatom layer formation on gold electrodes were examined. The data obtained were compared with those by the specular reflection method. Changes in reflectivity and angle of MOR(φ) of the electrode surfaces were measured during controlled potential electrolysis. The adsorption of adenine and FMN caused marked changes in reflectivity and the magnitude of change was found to depend on applied potential. The same situation was clearly evident in the potential dependence of φ. Adatom and bulk layers of Pb were formed on Au at more positive and negative potentials than at the standard redox potential of Pb²⁺ /Pb⁰. From the potential and wavelength dependence of φ, differences in magneto-optical properties between the adatom and the bulk layers could be seen.