In Situ Fabricated Three-Dimensional Composite Electrode of Mo–Ni ₃ S ₂ /Nickel Foam for Enhanced Electrocatalytic Hydrogen Evolution

Electrochemical water splitting is a crucial pathway for clean hydrogen production, but hydrogen evolution reaction (HER) electrodes often suffer from poor performance in alkaline conditions due to sluggish kinetics and weak durability. In this work, ammonium tetrathiomolybdate ((NH 4 ) 2 MoS 4 ) is used as a dual-functional precursor to transform Ni(OH) 2 nanosheets into 3D Mo–Ni 3 S 2 nanostructures. The fabricated electrode, Mo–Ni 3 S 2 /Nickel Foam, with an enlarged electrochemical active surface area, exhibits a low overpotential of 166 mV at 100 mA cm –2 in 1 M KOH and outstanding durability (>300 h). When integrated into anion-exchange membrane electrolyzers (AEMWE), it maintains stability for over 360 h at 500 mA cm –2 . The enhanced performance could potentially be attributed to the hierarchical nanostructure that provides abundant active sites, and the in situ fabrication method ensures the durability of the electrode.