Graphene oxide (GO) could be efficiently reduced to graphene on a Cu electrode through a novel electrocatalytic solid-to-solid reaction. Compared to glass carbon (GC) inertial electrodes, more oxygen-containing groups are removed on copper electrodes under the same electrochemical reduction conditions for de-oxygenation of GO nanosheets. Especially, Cu catalyst could electrochemically catalyze the elimination of sp³ carbon clusters in GO to restore sp² CC conjugated network of graphene relative to GC electrode.