Electrochemical oxidation of ascorbic acid mediated by Bi(2)O(3) microparticles modified glassy carbon electrode

Abstract

Bismuth oxide (Bi2O3) modified glassy carbon electrode (GCE) was fabricated by mechanical attachment. Electrochemical performance of microparticles of Bi2O3/GCE shows excellent electrooxidation of ascorbic acid (AA) in 0.1M KH2PO4 using cyclic voltammetry. The effect of Bi2O3/GCE is evident by the observation of high peak oxidation current of AA, showing an increase of 2 folds as compared to bare GCE. The detection limit of this modified electrode was found to be 8.1 × 10-6M. Hydrodynamic method (RDE) was used to determine the diffusion coefficient and rate constant of AA with values of 5.4 × 10-6 cm2s-1 and 2.7x10-3 cms-1 for unmodified electrode, while the values of 6.2x10-6 cm2s-1 and 2.3x10-3 cms-1 for GCE modified with Bi2O3, respectively.