Kinetic studies of glucose electrocatalytic oxidation on GC/Ni electrode

Danaee, I ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1002/kin.20721
  3. Publisher: 2012
  4. Abstract:
  5. Nickel-modified glassy carbon electrode (GC/Ni) prepared by galvanostatic deposition was used for the electrocatalytic oxidation of glucose in alkaline solutions where different electrochemical methods were employed. In cyclic voltammetry studies, in the presence of glucose an increase in the peak current of the oxidation of nickel hydroxide is followed by a decrease in the corresponding cathodic current. This suggests that the oxidation of glucose is being catalyzed through mediated electron transfer across the nickel hydroxide layer comprising nickel ions of various valence states. Under the chronoamperometric regime, the reaction followed a Cottrellian behavior and the diffusion coefficient of glucose was found to be 8 × 10 -6 cm 2 s -1. A mechanism based on the electrochemical generation of Ni 3+-active sites and their subsequent consumptions by glucose has been discussed, and kinetic parameters have been derived. The heterogeneous rate constants for the oxidation of glucose at the surface of modified electrodes were determined by rotating disk electrode using the Koutecky-Levich plots, which are in agreement with the data obtained by chronoamperometry
  6. Keywords:
  7. Active site ; Alkaline solutions ; Cathodic currents ; Electro-catalytic oxidation ; Electrochemical Generation ; ELectrochemical methods ; Galvanostatic deposition ; Glassy carbon electrodes ; Heterogeneous rate constant ; Kinetic study ; Mediated electron transfer ; Modified electrodes ; Nickel hydroxides ; Nickel ions ; Peak currents ; Rotating disk electrodes ; Valence state ; Chronoamperometry ; Cyclic voltammetry ; Diffusion ; Electrocatalysis ; Glass membrane electrodes ; Nickel ; Oxidation ; Rate constants ; Rotating disks ; Glucose
  8. Source: International Journal of Chemical Kinetics ; Volume 44, Issue 11 , 2012 , Pages 712-721 ; 05388066 (ISSN)
  9. URL: http://onlinelibrary.wiley.com/doi/10.1002/kin.20721/abstract