Interface Engineering of Ni ₂ P/NiSe ₂ for Energy‐Saving Urea/Urine Electrolysis

ABSTRACT Sustainable urea and urine electrooxidation are highly attractive for coupling energy conversion with environmental remediation. Herein, we report a powder catalyst of Ni 2 P/NiSe 2 nanoparticles embedded in N‐doped carbon nanofibers (Ni 2 P/NiSe 2 /NCNF), which exhibits markedly enhanced activity and stability compared with single‐component catalysts. Interfacial electron transfer from Ni 2 P to NiSe 2 establishes a built‐in electric field, leading to local bonding rearrangement and selective adsorption of urea intermediates, thereby accelerating the rate‐determining step. As a result, Ni 2 P/NiSe 2 /NCNF delivers a nearly five‐fold increase in current density and two orders of magnitude higher electron transfer and diffusion coefficient than Ni/NCNF. In situ Raman spectroscopy and post‐reaction analyses reveal surface reconstruction into high‐valence Ni species, with the heterostructure stabilizing the active surface. Furthermore, a urea/water co‐electrolysis device demonstrates substantial energy savings and stable hydrogen production. A current density of 98.83 mA cm − 2 is achieved in synthetic urine, with a long‐term stability of 48 h, showing its great potential in practical urine wastewater electrolysis. This study highlights the promise of Ni 2 P/NiSe 2 heterostructures for practical urea oxidation and advances the design of efficient bifunctional electrocatalysts for sustainable hydrogen generation.