Surface modification of a reactive metal or alloy by polyaniline for electrooxidation of iodide

Generally, an inert metal such as platinum is used for studying electrooxidation reactions. As a non-platinum metal or alloy undergoes corrosion and oxidation, it is not useful for this purpose. In the present study, surface modification of non-platinum metals by coating electronically conducting polymers for electrooxidation reactions was investigated. Polyaniline (PANI) was electrochemically deposited on stainless steel (SS) substrate by potentiodynamic method. The oxidation of I was studied by cyclic voltammetry and amperometry experiments. The I/I2 reaction couple was found to be quasireversible on the PANI/SS electrode. The amperometry study, conducted under fast mass transport conditions, has provided linear relationship between current and concentration of I. The data were analyzed and rate constant of the reaction was evaluated. Thus the oxidation of I, which does not occur on bare SS electrode, was shown to occur through electron transfer mediated by polyaniline