La doping NiFe layered double hydroxide nanosheet for efficient electrocatalytic overall water splitting

NiFe layered double hydroxides (LDHs) have been emerged as promising electrocatalysts for water splitting due to their tunable composition and layered architecture. However, their catalytic performance was limited by poor electrical conductivity and insufficient active site exposure. Herein, we reported a lanthanum-doped NiFe LDH nanosheet array (La-NiFe LDH) grown in situ on nickel foam by a simple hydrothermal method. Systematic characterization revealed that the incorporation of La induced lattice distortion and electronic structure modulation, leading to optimized metal-oxygen bonding and enhanced charge transfer kinetics. The optimized La 0.4- NiFe LDH catalyst demonstrated remarkable bifunctional electrocatalytic activity, requiring low overpotentials of 70 mV for the hydrogen evolution reaction at 10 mA cm - ² and 269 mV for the oxygen evolution reaction at 100 mA cm - ². Moreover, it demonstrated exceptional durability over 90 h of continuous operation. Besides, the two-electrode alkaline electrolyzer based on La 0.4 -NiFe LDH required only 1.49 and 1.58 V to achieve 10 and 100 mA cm - ² for overall water splitting, demonstrating superior performance compared to the commercial RuO 2 || Pt/C. This work highlights the potential of rare-earth doping as an effective strategy to engineer high-performance LDH-based electrocatalysts for sustainable hydrogen production.