Electroreduction of methyl viologen in methanol and silicate thin films prepared by the sol–gel method

Abstract Bulk methanol solutions of methyl viologen (paraquat) can be reversibly reduced to its blue cation radical on transparent ITO electrodes. The intensity of the coloration is directly proportional to voltage applied to the cell. Such effect does not occur for aqueous paraquat solutions. Reversible blue coloration can also be obtained for a MV2+-doped silicate thin film obtained by the sol-technique and sandwiched between two ITO plates.