Sulfidation adjust the valence states of metal ions enhancing alkaline seawater OER catalytic activity and stability for PBA−derived self–supporting NiFe sulfide

Abstract

Seawater, a prevalent resource, is gaining attention as a substitute for freshwater in hydrogen electrolysis. Nonetheless, the corrosion resistance of the anode to chloride ions still faces challenges. In this paper, NiFe PBA-S/NF was grown on nickel foam to promote effective electron conduction between the substrate and the catalyst, and the catalyst was enriched with redox reaction by adjusting the valence state of metal ions through sulfidation, which was beneficial to electrocatalytic kinetics and durability. Notably, it exhibited excellent performance in alkaline simulated seawater electrolytes, with an overpotential of 247 mV at 100 mA cm⁻² and remained stable for more than 55 h. In addition, we evaluated the effect of Cl⁻ ion concentration on catalyst performance and observed that the catalyst exhibited higher OER activity in alkaline simulated seawater with higher concentrations of Cl⁻. These results provide a solid experimental foundation for designing economically efficient seawater corrosion resistant electrolytic catalysts.