Electrocatalysis of ascorbic acid oxidation on a polyaniline derivatized electrode

Abstract

The results presented in this thesis reveal marked improvement in the oxidation characteristics of ascorbic acid, when the latter 1.s oxidized on a polyaniline derivatized carbon graphite working electrode. The pH of the system isalso observed to influence significantly the role of polyaniline in influencing the oxidation characteristics of the ascorbic acid. Polyaniline conductivity temperature. Experiments conducted with benzidine show that the is also shown to be dependent on latter catalyzes theelectropolymerization of aniline. It is also shown that, the oxidation potential of ascorbic acid on a benzidine modified polyaniline is reduced by approximately 140mV relative to that onbare polyaniline (no benzidine) electrode. Electrodeposition of tin and lead on a polyaniline modified electrode revealed that the latter has the best kinetics for metal ions reduction and stripping. A substantial enhancement of ascorbic acid oxidation is observed, even though the mechanism appear to involve metal ions as soluble mediators.