Interface-engineered amorphous-crystalline Mo/NixS heterojunctions for efficient urea electrooxidation
摘要
Developing nickel-based urea oxidation reaction (UOR) catalysts with low-cost, high activity is still in challenges. In this work, we report an amorphous Mo/crystalline NixS heterojunction (A/C-Mo/NixS) through a dual-phase engineering strategy involving sulfurization of nickel foam followed by magnetron-sputtered Mo deposition. Remarkably, the optimized A/C-Mo/NixS achieves an ultralow potential of 1.42 V (vs. RHE) at 50 mA cm⁻2, while maintaining stable operation over 60 h with negligible activity decay. Characterization results reveal that the crystalline NixS substrate provides excellent electrical conductivity through its ordered atomic arrangement, whereas the amorphous Mo overlayer creates abundant unsaturated coordination sites that synergistically optimize urea adsorption and intermediate stabilization. Particularly, the unique amorphous-crystalline interface induces strong electronic coupling between Mo and NixS, which not only accelerates the dehydrogenation kinetics of *CONH₂ intermediates but also effectively suppresses Ni leaching through enhanced charge transfer.