Activating lattice oxygen in local amorphous S-modified NiFe-LDH ultrathin nanosheets toward superior alkaline/natural seawater oxygen evolution.

ABSTRACT

The admire activity, selective and corrosion resistance electrocatalysts for oxygen evolution reaction (OER) are the bottleneck restricting seawater electrolysis owing to the side reactions of chloride ions (Cl-). Herein, we developed a local amorphous S-modified NiFe-LDH ultrathin nanosheets with large spacing on NiFe foam (la-S-NiFe-LDH/NFF) in-situ via the fast H2O2 assisted etching-anion regulation, resulting in a superior OER catalytic activity for seawater electrolysis. Benefitting from the local amorphous architecture induced by S, enhanced the metal-oxygen covalency, triggered lattice oxygen activity, and reduced the desorption energy of O2, the la-S-NiFe-LDH/NFF accelerated the OER progress via the lattice-oxygen-mediated (LOM) mechanism. Additionally, the preferential adsorbed OH- and reconstructed SO42- cooperated to prevent the proximity and erosion of Cl- and enhanced the corrosion resistance for seawater electrolysis. The assembled electrolyzer of Pt/C || la-S-NiFe-LDH/NFF possessed an industrial level of 500 mA cm-2 at 1.83 V potential for seawater electrolysis, and sustained response for 100 h.