Ruthenium-driven construction of amorphous/crystalline nickel‑iron layered double hydroxide via one-pot...

Developing highly efficient and cost-effective bifunctional electrocatalysts remains critical for scalable hydrogen production. Conventional nickel‑iron layered double hydroxide (NiFe-LDH) is constrained by sluggish hydrogen evolution reaction (HER) kinetics in overall water splitting. This work constructs ruthenium (Ru)-doped amorphous/crystalline heterostructured NiFe-LDH (Ru-a/c-NiFe) electrodes via rapid one-step electrodeposition using ultralow Ru loading (0.5 at.% ± 0.01 at.%). During crystallization, Ru doping specifically disrupts NiFe-LDH crystal growth, inducing localized coordination distortion to generate amorphous/crystalline interfaces that drive charge redistribution and synergistically activate dual functionality. The electrode demonstrates exceptional catalytic performance in 1.0 mol L^-1 KOH, requiring only 200 ± 1 mV overpotential at 1000 mA cm^-2 for HER and 270 ± 1 mV at 100 mA cm^-2 for oxygen evolution reaction (OER). Structural analysis indicates trace Ru doping creates structural defects (fractures/missed layers) and hydrophilic surfaces, improving mass transport. An industrial-scale anion-exchange membrane water electrolyzer (AEM-WEs) maintain 200-h stability at 1000 mA cm^-2. It also delivers outstanding alkaline seawater performance at 1.72 ± 0.01 V (100 mA cm^-2), confirming rapid interfacial reaction. This study establishes trace-doped heterostructure engineering as a new paradigm for industrial electrolyzer design.