Raman spectroscopic observation of adsorbates on Ag during electrochemical reduction of nitrobenzene

Abstract

Raman spectroscopic observation of the surface of a silver electrode during potentiostatic reduction of nitrobenzene in neutral and alkaline aqueous solutions has revealed adsorption of at least four chemical species at different potentials. At –0.5 V (vs. SCE), where the reduction starts, trans-azobenzene was detected with two other species. Raman bands of adsorbed aniline were observed at more cathodic potentials. When aniline was adsorbed from its aqueous solution, three of the above four species except azobenzene were detected on the electrode. Adsorbed aniline lies flat on the surface.