An MoS2/NiCo2O4 composite supported on Ni foam as a bifunctional electrocatalyst for efficient overall water splitting

Fabricating highly efficient and low-cost non-precious metal-based catalysts is a prerequisite for large-scale electrochemical water splitting in future renewable energy systems, yet remains a challenge. Herein, we describe the synthesis of cobalt-nickel oxide nanowires decorated with molybdenum disulfide nanosheets, directly grown on Ni foam (MoS2/NiCo2O4/NF), by a simple stepwise hydrothermal method and calcination process. Benefiting from a synergistic effect between MoS2 and NiCo2O4, the heterostructured catalyst accelerates water dissociation and exhibits superior catalytic activity under alkaline conditions, with a current density of 50 mA cm−2 at a low overpotential of 322 mV for the oxygen evolution reaction (OER) and an overpotential of 106 mV for the hydrogen evolution reaction (HER) (@ j = 10 mA cm−2). Notably, when used as both anode and cathode for overall water splitting, MoS2/NiCo2O4/NF achieved a quite low voltage of 1.62 V at 10 mA cm−2, and exhibited satisfactory stability for 16 h. Moreover, we have achieved continuous hydrogen and oxygen evolution at 1.606 V generated by using a solar panel, which is a promising route for solar-to-hydrogen conversion.