Defect-Rich NiFeAl-Layered Double Hydroxide Nanosheets for Efficient Electrocatalytic Oxygen Evolution Reaction

Atomic-level defect engineering is effective in optimizing the performance of transition metal-based catalytic materials. In this work, ultrathin 3 nm NiFeAl layered double hydroxide (NiFeAl-LDHs) nanosheets with rich cation vacancies were grown on nickel foam by a fast microwave-assisted process for the oxygen evolution reaction. The defect-rich NiFeAl-LDHs (D-NiFeAl-LDHs/NF) show an excellent overpotential (207 mV) and a Tafel slope (34 mV dec^–1) at 10 mA cm^–2. Experimental results and theoretical calculations show that the introduction of abundant cation vacancies effectively adjusts the electronic structure around reaction sites and optimizes the adsorption strength of reaction intermediates, thus significantly improving the oxygen evolution reaction catalytic performance.