Optimized valence state of Co and Ni in high-entropy alloy for high active-stable OER

High entropy alloy(HEA)exhibits potential water-splitting properties but are limited by the high energy consumption from preparation.Moreover,the complex atomic distribution endows the electronic structure regulation of HEA to remain challenging.Herein,the nanoporous NiCuMnCoFe(np-NCMCF)HEA was prepared by the high-energy ball milling coupled with de-alloying method.The introduced Fe markedly increases the proportion of Ni^(3+)and Co^(3+).