In-situ growth of hierarchical CuO@Cu3P heterostructures with transferable active centers on copper foam substrates as bifunctional electrocatalysts for overall water splitting in alkaline media

To fulfill the growing demand for green H2 fuels, low-cost, efficient, and stable bifunctional electrocatalysts must be developed. Herein, a hierarchical [email protected]3P/CF nanowire core-shell heterostructure with transferable active centers was developed for a bifunctional electrocatalyst with high activity. In this system, the transfer of electrochemically active centers between Cu3P and CuO is used to facilitate the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), respectively. Particularly, Cu3P acts as the active center for HER, while the active center shifts to CuO for OER reaction, and Cu3P acts as a co-catalyst to improve the conductivity of the system. Benefit from superhydrophilicity's high electrochemical surface area and synergistic effect of CuO core and Cu3P shell, and [email protected]3P/CF shown significant catalytic activity for hydrogen or oxygen evolution, requiring low overpotentials of 144 and 267 mV to achieve a current density of 10 mA cm−2. In addition, the assembled [email protected]3P/CF-based electrolyzer exhibit excellent overall water splitting performance with a low operating voltage of 1.75 V at 10 mA cm−2 and a negligible decrease in catalytic activity. This gives encouraging evidence for the utility of our catalysts in application areas.