Entropy–interface coupling in graphene-confined ZnNiFeCoCu high-entropy alloys for ampere-scale oxygen evolution

Abstract

The oxygen evolution reaction (OER) remains a major kinetic and durability bottleneck for industrial water electrolysis, where ampere-level currents intensify mass-transport resistance, gas accumulation and catalyst degradation. Here we report a graphene-coated ZnNiFeCoCu high-entropy alloy (Gr–HEA) electrocatalyst that integrates entropy-driven multisite catalysis, graphene-mediated interfacial confinement and a hierarchically layered electrode architecture. The multicomponent alloy lattice provides diverse local atomic environments that regulate oxygen-intermediate adsorption and interfacial charge transfer, whereas the conformal graphene shell forms a conductive and corrosion-resistant confinement layer that suppresses nanoparticle agglomeration, metal dissolution and interfacial degradation during anodic polarization. Meanwhile, the flake-like multilayered framework creates abundant interlayer voids and open channels, promoting electrolyte permeation and oxygen-bubble release under high-current operation. Benefiting from this entropy–interface–architecture synergy, Gr–HEA reaches 1.0 A cm −2 at 1.67 V versus RHE in 1.0 M KOH and sustains stable OER operation for over 210 h at 1.0 A cm −2 . When assembled as the anode in an anion-exchange-membrane electrolyser, it further maintains 1.0 A cm −2 for 114 h in 1.0 M KOH at 60 °C. This work establishes a composition–interface–architecture co-design strategy for durable, noble-metal-free OER catalysis.

The authors' abstract, as published at the source. Journal of Power Sources, 2026 · DOI ↗