Ultrathin heterogeneous nanolayer structure of FeCoNiCu multi-principal element alloy for robust water electrolysis

Abstract

Developing efficient, cost-effective alloy catalysts for the hydrogen evolution reaction (HER) is a promising strategy to convert electrical energy to chemical fuels efficiently, however, it remains challenge. Herein, a designed non-equimolar FeCoNiCu multi-principal element alloys (MPEAs) catalyst, fabricated via a simple physical metallurgy and chemical dealloying, exhibits HER performance comparable to commercial noble metal counterpart. The optimal (FeCoNi)₇₀Cu₃₀ (at.%) catalysts display a remarkable minimum overpotential of 34 mV (@10 mA cm⁻²) and a Tafel slope of 48 mV dec^-1. Meanwhile, the electrocatalyst exhibits excellent 24 h long-term durability stability at a high current density of −500 mA cm⁻²_. This is attributed to the multi-scale substructure of distinctive, self-supporting Colosseum-inspired skeletal structure, coupled with nanoscale porous architecture attached to ultra-thin serrated amorphous nanolayer structure, significantly enhancing the specific surface and active sites. This study provides a novel strategy for designing high-performance non-precious metal catalysts with heterogeneous substructures based on multicomponent combinations.