THE BEHAVOIUR OF CO-DOPED PBO2 ELECTRODE IN ACID MEDIA CONTAINING GLUCOSE OF CYSTEINE
The behaviour of Co-doped PbO2 electrode in 0.1 M H2SO4 solution containing glucose or cysteine was investigated. The doped lead dioxide electrode was electrodeposited from an electrolytic bath 0.5 M Pb(NO3)2 and 0.5 M Co (NO3)2 in galvanostatic conditions on the electromagnetic vibrated electrode. It was shown that working in sulphuric acid, after a high number of cycling in the potential range 0.5-2 V/SCE, the oxide electrode was degraded. This aspect was proved by SEM/EDX analysis. During the ten consecutive scanning in a restricted anodic potential range (from OCP of 1.2 V to 1.75 V/SCE), Co-doped PbO2 electrode was stable. A linear dependence between voltammetric currents and glucose concentration was obtained when glucose was added progressively. Cyclic voltammograms in the presence of cysteine have shown that cysteine had an inhibitor effect on the overall anodic process. EIS data regarding the electrochemical behaviour of Co-doped PbO2 electrode in the absence/presence of glucose were analysed at two potentials by three equivalent circuits.