The electrocatalytic behaviour of poly(aniline-co-4adpa) thin films in weakly acidic medium

Abstract

The electrocatalytic behaviour of poly(aniline-co-4adpa), Pan-4adpa, films against some redox couples and ascorbic acid was tested in aqueous buffering solutions of pH = 5. The film catalysed the redox process of all the couples investigated although it has been observed that positively charged species such as dopamine/dopaminequinone display more irreversible voltammetric behaviour than negative (ferro/ferricyanide) or neutral (hydroquinone/quinone) ones. The voltammetric results point that the catalytic sites of the Pan-4adpa are probably located at the surface of the film. The oxidation peak of ascorbic acid on Pan-4adpa films is shifted 170mV to more cathodic potentials with respect to the Pt with no generation of adsorbed residues.