Nucleophilicity‐S and Electrophilicity‐Ni Sites Over Ni@MoS ₂ Nanoreactors Enable Highly Efficient Hydrazine‐Assisted Hydrogen Production

ABSTRACT Hydrazine‐assisted water electrolysis offers a promising strategy for hydrogen production by significantly reducing the energy consumption while simultaneously enabling the remediation of hazardous hydrazine‐containing wastewater. However, the development of efficient bifunctional electrocatalysts remains challenging due to the incompatible reaction mechanisms of the hydrazine oxidation reaction (HzOR) and the hydrogen evolution reaction (HER). Herein, we design a hollow MoS 2 nanoreactor decorated with Ni nanoparticles (Ni x @MoS 2 ) featuring strong metal‐support interaction (SMSI). The SMSI‐induced interfacial electron redistribution creates nucleophilic S sites and electrophilic Ni sites, which synergistically lower H * adsorption energy barrier in HER and favor the N─N bond breakage in HzOR. The optimized Ni 2 @MoS 2 nanoreactor demonstrates exceptional bifunctional performance, achieving a current density of 100 mA cm – 2 at only 0.193 V in hybrid HzOR‐assisted water electrolysis, outperforming the most reported bifunctional catalysts. Moreover, the electrolyzer exhibits excellent long‐term operational stability, maintaining consistent performance over 200 h at 200 mA cm −2 . This work proposes a plausible N─N bond breakage pathway in HzOR enabled by SMSI strategy, offering new insights into the water electrolysis for green hydrogen production.