Cathodic Voltammetry of Nitrobenzene at Titanium in Micellar Solution

Abstract

The present study relates to electro-reduction of nitrobenzene in the presence of miceller aqueous solution of sodium dodecyl sulphate at titanium cathode, using cyclic voltammetric and titanium etching methods in a three-electrode system. Nitrobenzene gives single reduction peak (Ia) corresponding to the irreversible electrochemical reduction. However, at higher concentrations and lower sweep rates single peak splits into two cathodic peaks. These peaks correspond to reaction mechanisms, involving four-electron over-all change; first step, with one-electron transfer to form anion radical (peak I) similar to electron transfer observed in aqueous micellar media. While the second step involves protonation of anion radical followed by a three electron-addition (peak II) leading to the formation of phenylhydroxylamine. In the presence of SDS nitrobenzene solubilizes and reduces efficiently even at lower concentration; while in the absence of SDS reduction peak appears at relatively higher concentrations of nitrobenzene. This work targets the utility of titanium as cathode.