Sacrificial Vanadium Leaching Triggers Defect-Rich High-Valent Nickel Centers for Selective Seawater Oxygen Evolution

Abstract

Sluggish oxygen evolution kinetics and chloride-induced corrosion remain critical barriers to the development of efficient anode catalysts for seawater electrolysis. Here, we propose a defect-engineering strategy based on sacrificial vanadium(V) doping to construct a disordered NiFe layered double hydroxide (d-NiFe(OH)_x) nanosheet electrocatalyst. During electrochemical activation, V is rapidly leached, inducing the in situ formation of abundant non-metallic defects and lattice disorder. Experimental results, in-situ characterizations combined with density functional theory (DFT) calculations reveal that the disordered structure promotes the formation and stabilization of catalytically active, defect-rich high-valent NiOOH phases, enhances the adsorption of OH^– adsorption and suppress Cl^–- induced side reactions, and activates lattice oxygen participation in the OER process, thereby ensuring long-term catalytic activity during seawater OER. As a result, the catalyst achieves an industrial-level current density of 1.0 A·cm^–2 at 1.55 V in alkaline seawater and maintains excellent stability over 160 h, with a hydrogen production cost as low as $1745 per ton. This work offers a theoretical basis for designing efficient and corrosion-resistant OER catalysts for seawater electrolysis.

Keywords

Seawater electrolysis / Oxygen evolution reaction / Defect engineering / NiFe layered double hydroxide / Lattice oxygen mechanism

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2026 SIOC, CAS, Shanghai, & WILEY-VCH GmbH