Multicomponent nickel-molybdenum-tungsten-based nanorods for stable and efficient alkaline seawater splitting

The electrolysis of seawater for hydrogen production holds promise as a sustainable technology for energy generation. Developing water-splitting catalysts with low overpotential and stable operation in seawater is essential. In this study, we employed a hydrothermal method to synthesize NiMoWO_X microrods (NiMoWO_X@NF). Subsequently, an annealing process yielded a composite N-doped carbon-coated Ni₃N/MoO₂/WO₂ nanorods (NC@Ni₃N/MoO₂/WO₂@NF), preserving the ultrahigh-specific surface area of the original structure. A two-electrode electrolytic cell was assembled using NC@Ni₃N/MoO₂/WO₂@NF as the cathode and NiMoWO_X@NF as the anode, demonstrating exceptional performance in seawater splitting. The cell operated at a voltage of 1.51 V with a current density of 100 mA·cm^-2 in an alkaline seawater solution. Furthermore, the NC@Ni₃N/MoO₂/WO₂@NF || NiMoWO_X@NF electrolytic cell exhibited remarkable stability, running continuously for over 120 h at a current of 1100 mA·cm^-2 without any observable delay. These experimental results are corroborated by density functional theory calculations. The NC@Ni₃N/MoO₂/WO₂@NF || NiMoWO_X@NF electrolyzer emerges as a promising option for industrial-scale hydrogen production through seawater electrolysis.