Ascorbic acid oxidation at nonmodified and copper-modified polyaniline and poly-ortho-methoxyaniline coated electrodes

The electrochemical oxidation of ascorbate ions is comparatively studied at polyaniline (PANI) and poly-ortho-methoxyaniline (POMA) layers in absence and presence of electrodeposited copper species. In comparison to PANI, POMA layers allow decreasing the overpotential necessary for driving the ascorbate oxidation reaction. A nonlinear dependence of the ascorbate oxidation current on the polymer layer redox charge is found. Copper electrodeposited in PANI and POMA layers is electrocatalytically active for the investigated reaction. Two separate oxidation waves are observed in the case of Cu-PANI whereas a single ascorbate oxidation wave and enhanced Currents are found in the Cu-POMA case.