A Strongly Coupled Ag(S)@NiO/Nickel Foam Electrode Induced by Laser Direct Writing for Hydrogen Evolution at Ultrahigh Current Densities with Long‐Term Durability

Abstract Highly active, durable, and cost‐effective electrodes for hydrogen evolution reaction (HER) at ultrahigh current densities (≥1 A cm −2 ) are extremely demanded for industrial high‐rate hydrogen production, but challenging. Here, a robust strongly coupled Ag(S)@NiO/nickel foam (NF) electrode is reported. Taking advantage of millisecond laser direct writing in liquid nitrogen technique, lattice‐matched and coherent interfaces are formed between Ag nanoparticles with stacking faults (denoted by Ag(S)) and NiO nanosheets, leading to strong interfacial electronic coupling, not only promoting H 2 O adsorption and dissociation on Ni 2+ but also enhancing H * adsorption on intrinsically inactive but most electrically conductive Ag. Strong chemical bonding is established at NiO/NF interface, guaranteeing rapid electron transfer and excellent mechanical durability under high‐rate hydrogen evolution. The physicochemically stable electrode achieves record‐low alkaline HER overpotential of 167 and 180 mV at 1 and 1.5 A cm −2 , respectively, along with negligible activity decay after 120 h test at ≈1.5 A cm −2 , surpassing reported non‐platinum group metal electrocatalysts.