High-entropy MnCoCuZnAlSe2 nanosheet arrays for highly efficient alkaline oxygen evolution reaction

The oxygen evolution reaction is the primary obstacle in the electrochemical breakdown of water; whereas transition metal selenides exhibit remarkable OER activity, their stability is compromised by the oxidative dissolution of selenium. The high-entropy materials can provide a feasible strategy to solve this problem due to their multi-element synergy and entropy stabilization effect. Here, we designed novel high-entropy MnCoCuZnAlSe 2 electrocatalysts with ultra-low overpotential (190 mV@10 mA cm -2 ) and exceptional endurance (500 h@10 mA cm -2 ), which outperform other selenide and IrO 2 catalysts. The high entropy effect was experimentally confirmed to inhibit selenium dissolution and improve the stability of transition metal selenides. Calculations using Density Functional Theory suggest that cobalt is actually MnCoCuZnAlSe 2 's true active center. The extraordinary OER properties of high-entropy selenides offer great opportunities for the design of ideal catalysts for practical applications.