Cobalt–nickel layered double hydroxide on hollow Co₃S₄/CuS derived from ZIF-67 for efficient overall water splitting

Electrochemical water splitting is one of the most efficient strategies to generate clean energy H2. Herein, a novel hollow Co3S4/CuS@CoNi-LDH nanocomposite was designed. This hollow Co3S4/CuS@CoNi-LDH achieved OER overpotential of 220 mV, HER overpotential of 136 mV, respectively, at the current density of 10 mA cm−2. Notably, the hollow Co3S4/CuS@CoNi-LDH serving as both anode and cathode is assembled into a two-electrode water splitting device, and the potential of no more than 1.74 V is required to achieve the overall water splitting efficiency of 10 mA cm−2. This work provides a promising bifunctional catalyst for overall electrochemical water splitting.