Doping-driven dual heterogeneous interfacial structures boosting the durability of industry-compatible water splitting at high current density

Developing highly stable electrocatalysts under industry-compatible current densities (>500 mA cm⁻²) in an anion-exchange membrane water electrolyzer (AEMWE) is an enormous challenge for water splitting. Herein, based on the results of density function theory calculations, a dual heterogeneous interfacial structured NiSe/Fe-Ni(OH)₂ catalyst was subtly designed and successfully prepared by electrodepositing Fe-doped Ni(OH)₂ on NiSe-loaded nickel foam (NF). Fe doping-driven heterogeneous structures in NiSe/Fe-Ni(OH)₂ markedly boost catalytic activity and durability at industrially compatible current densities in single hydrogen and oxygen evolution reactions under alkaline conditions. In particular, NiSe/Fe-Ni(OH)₂ shows a negligible performance loss at 600 mA cm⁻² at least 1,000 h for overall water splitting, a distinguished long-term durability acting as AEMWE electrodes at 600 mA cm⁻² and 1 A cm⁻² at 85 °C for at least 95 h. Owing to Fe doping-induced strong synergetic effect between Ni and Fe, dual heterostructure-promoted charge transfer and redistribution, abundant catalytic active sites, and improvement of stability and durability, a mechanism of Fe doping-driven heterogeneous interfacial structure-promoted catalytic performance was proposed. This study provides a successful example of theory-directed catalyst preparation and pioneers a creative strategy for industry-compatible water splitting at high current density.