Pulse-electrodeposited Cr/Fe–Ni(OH)2 on nickel felt for scalable fabrication of a highly efficient and stable anode for seawater splitting

Abstract

Electrocatalytic anodes applied in seawater splitting should be highly efficient and resistant to corrosion by chloride ions. Herein, a pulse electrodeposition method has been applied to fabricate Cr/Fe–Ni(OH)₂-based catalysts on nickel felt. Cr, acting as a Lewis acid site, locally enriches OH⁻ ions, thereby enhancing chloride corrosion resistance while regulating the electronic structure of adjacent nickel/iron sites. As a result, the as-prepared anode achieved a low overpotential of 203.8 mV at a current density of 10 mA cm⁻². Moreover, this method for the production of the anode is scalable. A 4 cm × 4 cm anode assembled into an anion-exchange membrane electrolyzer achieved a current density of 1000 mA cm⁻² at a low cell voltage of 1.837 V. Overall, this work provided a feasible method to prepare large-scale anodes with highly efficient activity and high resistance to Cl⁻ in seater splitting.