Raman spectra of aniline adsorbed on an Ag electrode in acidic solutions

Abstract

The adsorption of aniline on an Ag electrode in acidic aqueous solutions has been studied by surface-enhanced Raman scattering. Adsorption, both as neutral and protonated forms, was observed to depend upon the electrode potential. The choice of halide ions used as the supporting electrolyte as well as the pH of the solution affected the stability of the protonated form on the surface. The geometry of adsorption was also studied by the change in intensities of the Raman bands upon adsorption. It was concluded that the anilinium ion is adsorbed Coulombically in at least two different geometries on halide ions which remain on the electrode surface.