Electrochemical oxidation of ascorbic acid mediated by Bi2O3 microparticles modified glassy carbon electrode.

• Main Authors: Mohammed Zidan,, Tan, Wee Tee, Abdullah, Abdul Halim, Zainal, Zulkarnain, Goh, Joo Kheng
• Format: Article
• Language: English; English
• Published: Electrochemical Science Group 2011
• Online Access: http://psasir.upm.edu.my/id/eprint/24775/1/Electrochemical%20oxidation%20of%20ascorbic%20acid%20mediated%20by%20Bi2O3%20microparticles%20modified%20glassy%20carbon%20electrode.pdf; http://psasir.upm.edu.my/id/eprint/24775/; http://www.electrochemsci.org/

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.