Active Site Implantation for Ni(OH)2 Nanowire Network Achieves Superior Hybrid Seawater Electrolysis at 1 A cm−2 with Record‐Low Cell Voltage

Abstract

AbstractDirect seawater electrolysis provides a grand blueprint for green hydrogen (H2) technology, while the high energy consumption has severely hindered its industrialization. Herein, a promising active site implantation strategy is reported for Ni(OH)2 nanowire network electrode on nickel foam substrate by Ru doping (denoted as RuNi(OH)2 NW2/NF), which can act as a dual‐function catalyst for hydrazine oxidation and hydrogen evolution, achieving an ultralow working potential of 114.6 mV to reach 1000 mA cm−2 and a small overpotential of 30 mV at 10 mA cm−2, respectively. Importantly, using the two‐electrode hydrazine oxidation assisted seawater electrolysis, it can drive a large current density of 500 mA cm−2 at 0.736 V with over 200 h stability. To demonstrate the practicability, a home‐made flow electrolyzer is constructed, which can realize the industry‐level rate of 1 A cm−2 with a record‐low voltage of 1.051 V. Theoretical calculations reveal that the Ru doping activates Ni(OH)2 by upgrading d‐band centers, which raises anti‐bonding energy states and thus strengthens the interaction between adsorbates and catalysts. This study not only provides a novel rationale for catalyst design, but also proposes a feasible strategy for direct alkaline seawater splitting toward sustainable, yet energy‐saving H2 production.