Strain-engineering-regulated Al0.6CrFe2Ni2 high entropy alloy enhances electrocatalytic water oxidation

Oxygen evolution reaction (OER) is an important semi-reaction in water decomposition. Currently, many OER catalysts have been reported, but most OER catalysts with high catalytic activity are plagued by complicated synthesis, high cost, and poor stability. Herein, we first report the bulk Al0.6CrFe2Ni2 high entropy alloy (HEA) as the catalyst for OER. The cryogenic treatment method is selected to improve the degree of lattice distortion, resulting in the strain effect on the catalyst surface, thereby improving the catalytic activity. The optimized electrode has an overpotential of 259.5 mV at 10 mA cm−2 with a Tafel slope of 47.9 mV dec−1 and can be stabilized for 24 h in 1 M KOH solution. This work will provide an example reference for the development of low-cost and high-stability OER catalysts.