Facile fabrication of CuO microcube@Fe–Co3O4 nanosheet array as a high-performance electrocatalyst for the oxygen evolution reaction

Abstract

A “top-down” tactic was offered to synthesize highly efficient electrocatalysts for the oxygen evolution reaction (OER), in which a CuO microcube supported Fe doped Co₃O₄ nanosheet composite was obtained using a facile unipolar pulse electrodeposition (UPED) method combined with a thermal treatment method. Specifically, an Fe doped Co(OH)₂ shell was electrodeposited on the electrode with a Cu particle core simultaneously. Interestingly, it is found that Fe–Co(OH)₂ nanosheets grew around the Cu particle core. As a result, a novel electrocatalyst with the Cu cube core and the Fe–Co(OH)₂ nanosheet shell was successfully formed in one step. After subsequent thermal oxidation treatment, the CuO microcube@Fe–Co₃O₄ nanosheet core–shell composite was obtained on the electrode. Benefiting from the one-step electrodeposition, the composite electrode with a smart 3D hierarchical structure as well as the intrinsic activity of Fe–Co₃O₄ nanosheets showed a remarkably enhanced catalytic performance for OER, which revealed a low overpotential of 232 mV at 10 mA cm⁻² current density.