Dynamic Migration of Ag Efficiently Modulated Electronic Structure and Impressed Chlorine Corrosion of NiFe-LDH for Seawater Oxidation.

Seawater electrolysis is a promising route for hydrogen production. However, the elevated concentration of Cl in seawater can cause the serious corrosion of electrode materials, which limits the large-scale application of seawater splitting for the generation of green hydrogen. Herein, nickel iron layered double hydroxide@Ag/iron foam (NiFe-LDH@Ag/IF) composites are synthesized using a two-step method at room temperature. The introduction of Ag not only induces the electron density redistribution of NiFe-LDH to promote the formation of NiFeOOH as the catalytically active sites, but also impress the corrosion of chloride ions during the seawater oxidation. The as-prepared NiFe-LDH@Ag/IF only requires a low overpotential of 255 mV at a current density of 500 mA cm in alkaline solution, and it can stably operate for 1000 h without degradation. Importantly, the formed AgCl nanoparticles loaded on the surface of NiFe-LDH nanosheets can effectively prevent the corrosive effect of Cl during the seawater oxidation process. Thus, NiFe-LDH@Ag/IF can maintain high catalytic activity and work stably for 1000 h at high current density of 500 mA cm for seawater oxidation. This study presents a simple method for preparing self-supported electrocatalysts with excellent corrosion resistance and high catalytic activity in alkaline seawater oxidation.