Quenching induced the amorphous urea-philic phosphate shell on B-Ni2P/NF to coordinate the electronic configuration of Ni active sites for efficient urea oxidation kinetics

Developing an effective strategy to controllably construct phosphate shells on phosphides remains a challenge because of the sluggish kinetics of the oxygen evolution reaction (OER). In this work, Ni(PO x )@B-Ni 2 P/NF electrodes with an amorphous phosphate shell were fabricated using a phosphorization–quenching strategy. Remarkably, Ni(PO x )@B-Ni 2 P/NF requires only 81 mV and 1.333 V to deliver a current density of 100 mA cm −2 for the hydrogen evolution reaction (HER) and urea oxidation reaction (UOR), respectively—outperforming Pt/C@NF and previously reported Ni-based electrodes. The self-assembled Ni(PO x )@B-Ni 2 P/NF(+)||Ni(PO x )@B-Ni 2 P/NF(−) configuration achieves 1 A cm −2 at only 1.414 V for urea-assisted water splitting, indicating strong potential for industrial application. In situ Raman spectroscopy, combined with theoretical calculations, reveals that the amorphous phosphate shell, which exhibits strong urea adsorption capacity, optimizes the electronic configuration of the Ni(PO x )@B-Ni 2 P heterointerface. It also suppresses the peroxidation of internal Ni active sites into Ni–OOH by-products with high *COO adsorption energy. The resulting low-valent Ni O active species reduce the *COO adsorption energy and promote C N bond cleavage in urea, thereby accelerating UOR kinetics. These findings offer new design strategies for phosphate@phosphide electrodes tailored for industrial hydrogen production coupled with urea degradation.