Facile fabrication of self-supporting porous CuMoO4@Co3O4nanosheets as a bifunctional electrocatalyst for efficient overall water splitting

Research shows that redox complementarity and synergism among the ingredients of heterogeneous catalysts can enhance the performance of the catalyst. In this research, a porous CuMoO₄@Co₃O₄ nanosheet electrocatalyst is prepared, which is uniformly decorated on nickel foam (NF) by hydrothermal reactions and the impregnation method. The CuMoO₄@Co₃O₄ is an efficient bifunctional catalyst with prominent electrocatalytic activity and durability. It requires overpotentials of only 54 and 251 mV to obtain current densities of 10 and 50 mA cm^-2 for the cathodic hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER) in 1.0 mol L^-1 KOH, corresponding to Tafel slope values of 98.8 and 87.4 mV dec^-1, respectively. Furthermore, the CuMoO₄@Co₃O₄ shows excellent stability of 120 h chronopotentiometry at a current density of 100 mA cm^-2 for the HER/OER. Notably, an alkaline electrolyzer (with CuMoO₄@Co₃O₄ as the HER and OER electrodes) can deliver a current density of 10 mA cm^-2 at a low voltage of 1.51 V. The catalytic activity of CuMoO₄@Co₃O₄ can be attributed to the structure of the porous nanosheets and the synergistic effect between CuMoO₄ and Co₃O₄.