Co and P dual-doped Ni3S2 directly grown on nickel foam as a robust noble metal-free electrocatalyst for urea assisted water electrolysis

초록

Developing efficient and durable non-noble metal electrocatalysts is critical for sustainable hydrogen production and wastewater treatment. Herein, the cobalt and phosphorus dual-doped Ni3S2 directly grown on nickel foam (Co-Ni3S2-P/NF) is rationally designed and synthesized via hydrothermal growth of a NiCo-PBA intermediate followed by sequential sulfidation and phosphidation. The hierarchical architecture ensures homogeneous dispersion of active sites and a large electrochemically accessible surface area, while dual heteroatom doping modulates the electronic structure, enhances charge transfer, and improves surface hydrophilicity. Benefiting from these synergistic effects, Co-Ni3S2-P/NF delivers low overpotentials of 351 mV and 189 mV at 100 mA cm-2 for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. Moreover, it requires only 1.37 V to drive the urea oxidation reaction (UOR) at the same current density, with a small Tafel slope of 63.55 mV dec- 1. A symmetric two-electrode cell assembled with Co-Ni3S2-P/NF delivers 50 mA cm- 2 at 1.78 V for overall water splitting and only 1.62 V under urea-assisted conditions, highlighting its significant

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