Electrochemistry of hydrogen peroxide reduction reaction on carbon paste electrodes modified by Ag- and Pt-supported carbon microspheres

Abstract

A simple and facile hydrothermal methodology for preparation of carbon microspheres supported with silver or platinum is presented. Electrocatalytic properties of modified carbon microspheres are tested against the electrochemical reduction reaction of hydrogen peroxide. As revealed by transmission electron microscopy, silver and platinum are immobilized on the surface of carbon microspheres in a form of nanoparticles. In addition, scanning electron microscopy reveals coexistence of smooth surface spherical-shaped carbon microspheres together with clusters that resemble a bunch-of-grapes. Carbon paste electrodes in combination with cyclic and square-wave voltammetry are used to study electrocatalytic properties of carbon microspheres. Voltammetric data are analyzed in light of the theory for simple irreversible electrode reaction. Correlation between experimental and theoretical data implies the highest electrocatalytic effect in the case of silver-modified carbon microspheres, though the electrode mechanism is more complex than theoretically predicted.