Cyclic Voltammetry and In Situ Laser Raman Spectroscopy Studies of Electrogenerated Methyl Viologen Radical Cation

Abstract

The electrogeneration of methyl viologen radical cation (MV+) at a silver electrode in chloride solution has been studied. Evidences for the adsorption of MV+ or a related species have been obtained by cyclic voltammetry and in situ laser Raman spectroscopy measurements. It was observed that electrode cycling and high chloride ion concentration stabilize the adsorbed state of MV+ at the electrode. It appeared possible to distinguish between Raman signal due to surface species and to species dissolved in the solution. Characteristic spectra are presented. The Raman technique also seems capable of detecting submonolayer quantities of MV+ and to be useful for monitoring concentration changes of the radical cation.