Tannic acid salts-modified CoFe-layered double hydroxide boosts the stable seawater oxidation at an industrial-level current density

Abstract

Seawater electrolysis for green hydrogen production is a promising approach toward achieving carbon neutrality. However, the abundance of Cl– in seawater can severely corrode catalytic sites, significantly reducing the lifespan of seawater electrolysis systems. Herein, we present metal ions-chelated tannic acid nanoparticles anchored on the CoFe layered double hydroxide nanosheet array on nickel foam (CoFe LDH@CoFe-TA/NF), synthesized via an interfacial coordination assembly method, serving as an efficient and stable electrocatalyst for alkaline seawater oxidation (ASO). The formed CoFe-TA nanoparticles promote the reconstruction and generation of CoFe oxy(hydroxide), which not only drives excellent ASO performance but also enhances resistance to chlorine-induced corrosion. In addition, the CoFe-TA ligand network effectively inhibits metal ions leaching and stabilizes active sites. As a result, CoFe LDH@CoFe-TA/NF electrode requires a low overpotential of only 379 mV to obtain a current density of 1000 mA cm–2 in 1 M KOH + seawater. Furthermore, the electrode also shows a stable operation for 450 h at an industrial-level current density, underscoring its potential for sustainable energy applications.