Preparation of nanoporous Cu/Cu2O composites by anodic oxidation and their electrocatalytic performance towards methanol oxidation

Abstract Nanoporous Cu/Cu2O (NP-Cu/Cu2O) composites with a three-dimensional bicontinuous heterostructure are prepared by anodic oxidation of nanoporous copper (NP-Cu). The effects of electrolyte (pH 7–13) and anodic oxidation potential (0.1–1.0 V vs. SCE) on the morphologies and electrocatalytic performances of NP-Cu/Cu2O composites are investigated. The Cu2O/Cu content ratio increases with the increase of anodic oxidation potential, but decreases with the increase of pH value. The pore/ligament width ratio of NP-Cu/Cu2O composites prepared in pH 9–13 electrolytes is in the range of 0.6–1.0. The onset potential of NP-Cu/Cu2O negatively shifts, and the oxidation peak current density of NP-Cu/Cu2O composites prepared in pH 7–11 electrolytes is higher than that of NP-Cu. NP-Cu/Cu2O composite prepared in pH 11 electrolyte at anodic oxidation potential of 0.7 V exhibits the best electrocatalytic performance towards methanol oxidation.