Oxalate anions-intercalated NiFe layered double hydroxide as a highly active and stable electrocatalyst for alkaline...

Seawater electrolysis is gaining recognition as a promising method for hydrogen production. However, severe anode corrosion caused by the high concentration of chloride ions (Cl^-) poses a challenge for the long-term oxygen evolution reaction. Herein, an anti-corrosion strategy of oxalate anions intercalation in NiFe layered double hydroxide on nickel foam (NiFe-C₂O₄^2- LDH/NF) is proposed. The intercalation of these highly negatively charged C₂O₄^2- serves to establish electrostatic repulsion and impede Cl^- adsorption. In alkaline seawater, NiFe-C₂O₄^2- LDH/NF requires an overpotential of 337 mV to gain the large current density of 1000 mA cm^-2 and operates continuously for 500 h. The intercalation of C₂O₄^2- is demonstrated to significantly boost the activity and stability of NiFe LDH-based materials during alkaline seawater oxidation.