NiFe layered double hydroxide with intercalated fluorosilicate anions for industrial level alkaline seawater oxidation

Abstract

Seawater electrolysis for hydrogen production is efficient and promising, but chloride ions (Cl–) cause severe anode corrosion, limiting its potential. In this study, we present the intercalation of fluorosilicate anions into NiFe layered double hydroxide nanosheet arrays on Ni foam (SiF62–-NiFe LDH/NF) as an industrial level alkaline seawater oxidation catalyst. SiF62–-NiFe LDH/NF achieves a current density of 1000 mA cm–2 at an overpotential of 371 mV, and maintains good stability for 1000 h. It also exhibits robust stability at higher current density of 1.5 or 2 A cm–2, In situ Raman spectroscopy confirm that SiF62– promotes the generation of γ-NiOOH and repels Cl−, demonstrating excellent tolerance under extreme conditions.