Engineering Nanowire Array Structure of Copper Oxide/Cuprous Oxide for Enhanced Oxygen Evolution Reaction

Electrocatalytic activity towards oxygen evolution reaction (OER) could be significantly enhanced through generating nanowire array structure of transition-metal oxide on the substrate surface. However, the construction of nanowire array structure generally requires a complex process. Herein, we report a facile and effective approach in situ to generate the three-dimensional (3D) nanowire arrays of copper oxide/cuprous oxide (CuO/Cu2O) for enhanced OER. The resulting typical sample presents an excellent electrocatalytic OER performance with a low overpotential (246 mV) at 10 mA cm−2 and long-term stability, which may be attributed to the characteristics of nanowire array, mesoporous structures and high surface area for CuO/Cu2O composite as follows. The nanowire array and mesoporous structures are beneficial for the diffusion and transport of electrons and reactants, and the high surface area has the potential to provide more active sites in improving the OER activity. This research provides a worthy inspiration for preparation of CuO/Cu2O electrocatalyst with nanowire array structure by in situ conversion route.