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Electrocatalytic oxidation of ascorbic acid mediated by ZnO microcrystalline modified glassy carbon electrode.


Citation

Tan, Wee Tee and Zidan, Mohammed and Zainal, Zulkarnain and Abdullah, Abdul Halim and Goh, Joo Kheng (2010) Electrocatalytic oxidation of ascorbic acid mediated by ZnO microcrystalline modified glassy carbon electrode. Oriental Journal of Chemistry, 26 (1). pp. 45-52. ISSN 0970-020X

Abstract

Modification of a glassy carbon (GC) electrode surface by adhered microparticles of zinc oxide (ZnO) using electrochemical performance of microparticles of ZnO/GC electrode shows excellent electrocatalytic activity towards the oxidation of ascorbic acid in 0.1 M KH2PO4 electrolyte solution by cyclic voltammetry (CV). This paper seeks to critically examine the modification of GC electrode with Zinc oxide microparticles and the effect on oxidation of ascorbic acid using cyclic voltammetry technique. ZnO/GC electrode exhibited obvious enhancing and electrocatalyzing effect as it causes the oxidation current of ascorbic acid to increase by 1.5 times as compared to bare GC electrode. The sensitivity under conditions of cyclic voltammetry is significantly dependent on pH and ZnO dosage. The variation of scan rate study shows that the system undergoes diffusion-controlled process. Diffusion coefficient and rate constant of ascorbic acid were determined using hydrodynamic method (rotation disk electrode)with values of 5.4 x 10-6cm2s-1 and 2.5x 10-3cms-1 respectively for unmodified electrode, while the values of diffusion coefficient and rate constant of ascorbic acid using ZnO/GC electrode were 5.7 x10-6cm2s-1 and 2.1x10-3cms-1 respectively.


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Additional Metadata

Item Type: Article
Divisions: Faculty of Science
Publisher: Oriental Scientific Publishing
Keywords: Zinc oxide microcrystalline; Modified GC electrode; Ascorbic acid; Cyclic voltammetry.
Depositing User: Najwani Amir Sariffudin
Date Deposited: 02 May 2014 08:26
Last Modified: 15 Jan 2016 08:37
URI: http://psasir.upm.edu.my/id/eprint/14459
Statistic Details: View Download Statistic

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