Electrocatalytic activity of silver modified gold film for glucose oxidation and its potential application to fuel cells

The electrocatalytic activity of the submonolayer silver modified gold film electrodes for the glucose oxidation in alkaline solution and the influences of the electrode size, the glucose concentration and the supporting electrolyte concentration on the reaction were investigated using cyclic voltammetry. The performance of a fuel cell utilizing the glucose oxidation was also evaluated. Gold film electrodes of large size were prepared by evaporating gold onto micas. The submonolayer modification of gold electrodes by silver underpotential deposition resulted in about 0.1 V negative shift in peak potential and a little larger current in the glucose oxidation, and the peak current obtained was proportional to the electrode size and the glucose concentration. The oxidation peak was also affected by the supporting electrolyte, showing a positive shift in potential and a drop in current if a certain concentration of sodium hydroxide was not reached. The catalytic activity of the silver modified gold film electrodes was stable, and a certain power of electricity was obtained with a glucose-air fuel cell. (c) 2006 Elsevier B.V. All rights reserved.