▎ 摘　　要

We electrochemically reduce graphene oxide to control the oxygen functional species. The electrocatalytic activities toward L-ascorbic acid oxidation of as-received and electroreduced graphene oxides are compared by cyclic voltammetry and surface changes by XPS and XRD analysis. The observations represent that edge-like oxygen functional groups by optimal electrochemical reduction result in the higher electrocatalytic activity. (C) 2011 Elsevier B.V. All rights reserved.