Engineering the strong metal–support interaction of Ni nanoparticles and MoO ₂ nanowires for efficient hydrogen evolution reaction

Abstract Developing highly active and cost‐effective catalysts for the hydrogen evolution reaction (HER) is crucial for alkaline water electrolysis, but it remains a significant challenge. Herein, nickel (Ni) nanoparticles composite partially confined in molybdenum dioxide (MoO 2 ) lattices was developed via a facile strong metal–support interaction (SMSI) tuning strategy. Experimental analyses revealed that the regulation of the electronic structure of Ni@MoO 2 by SMSI significantly alleviated the work function of Ni@MoO 2 , accelerating electron transfer and optimizing adsorption of hydrogen intermediates, thereby boosting the HER activity. The optimized Ni@MoO 2 catalyst exhibited an overpotential of only 18 and 30 mV to reach a current density of 10 mA cm −2 , in alkaline freshwater and seawater, respectively, surpassing the commercial Pt/C catalysts. A two‐electrode system with Ni@MoO 2 as a cathode required a voltage of 1.46 V to attain the current density of 10 mA cm −2 , with no performance degradation after 500 h. This two‐electrode configuration exhibited a solar‐to‐hydrogen conversion efficiency of up to 20.10% when used in constructing a solar‐powered water electrolysis electrolyzer. This study provides a promising strategy for designing stable and efficient catalysts for industrial hydrogen production.