La-Ni2P/NiSe@C/NF Heterojunction Electrocatalysts: Synergistically Promoting Urea Oxidation Reaction through Lanthanum Doping and Interface Engineering

To address the escalating global energy demand and advance sustainable hydrogen production, we report the rational design of a carbon-encapsulated La-doped Ni 2 P/NiSe heterojunction electrocatalyst on nickel foam (La-Ni 2 P/NiSe@C/NF) via synergistic La doping and interface engineering for enhanced urea oxidation reaction (UOR). La induces porous, wrinkled nanosheets, boosting surface area (11.89 m 2 g -1 ), enhancing active site exposure. The Ni 2 P/NiSe heterointerfaces generate built-in electric fields that accelerate interfacial charge transport. XPS, EXAFS, and in situ Raman confirm La doping modulates Ni 3+ electronic structure, thereby shifting the Ni²⁺/Ni³⁺ redox transition to lower potentials, thereby shifting the Ni 2+ /Ni 3+ redox transition to lower potentials. The La-Ni 2 P/NiSe@C/NF exhibits excellent UOR activity in an alkaline electrolyte, delivering a current density of 10   mA   cm -2 at 1.296   V (vs. RHE). Remarkably, it achieves a low Tafel slope of 32.73 ± 0.73   mV dec -1 . These performance metrics surpass both control samples and state of the art benchmark materials. Moreover, a two-electrode electrolyzer assembled with La-Ni 2 P/NiSe@C/NF||Pt/C/NF exhibits exceptional 250   h stability at 50   mA   cm -2 , underscoring the efficacy of rare-earth doping and heterointerface engineering for high-performance UOR.