Design of amorphous high-entropy FeCoCrMnBS (Oxy) hydroxides for boosting oxygen evolution reaction

The efficient electrocatalysts towards the oxygen evolution reaction (OER) are vital for water splitting. Herein, a novel FeCoCrMnBS high-entropy (Oxy) hydroxide (HEH) is synthesized on a nickel foam (NF) surface via a facile approach. The FeCoCrMnBS HEH possesses a porous morphology composed of plentiful ultra-thin nanosheets with the amorphous structure. The obtained FeCoCrMnBS/NF electrode exhibits exceptional electrocatalytic OER activity in alkaline solution, requiring only 290 ​mV overpotential for 100 ​mA ​· ​cm⁻². Moreover, this catalyst displays a long-term durability of over 120 ​h at 10 ​mA ​· ​cm⁻². The enhanced catalytic performance benefits from the unique amorphous structure and the positive synergy effect between B and S, promoting the formation of SO₄²⁻ and thus weakening the adsorption of intermediates in OER on the catalyst surface. This work provides a new strategy for the design of desirable OER electrocatalysts.