Mechanically mixing copper and iron at subnanometric scale for catalyzing hydrogen evolution reaction

Abstract

Economically viable catalysts with high activity and stability are highly demanded for water electrolysis. Herein, we choose low-cost copper and iron as the raw materials, and mechanically mix them into at the subnanometric scale to obtain a self-supporting electrode. The interaction of copper and iron optimizes the d-band center and adsorptive capability of the catalyst, thus significantly improving the catalytic properties of hydrogen evolution reaction (HER). The CuFe catalyst achieves ultralow overpotentials of 67 mV at 10 mA cm⁻² and 687 mV at 1000 mA cm⁻². As well, the catalyst presents excellent stability, with only a 3.03 % drop in the initial current density after 1000 h of operation at 1 A cm⁻². Compared to nickel-based catalysts, the CuFe catalyst proves to be superior in terms of catalytic activity, stability, and price, showing great potential on industrial applications.