Construction of Interfacial P−Ni Bonding for Enhanced Hydrogen Evolution Performance of P‑Doped C₃N₄/Ni Photocatalysts

Interface defects are one of the main factors for inefficient photoelectric conversion of nanocomposites, which is also suitable for the photocatalytic nanosystem containing photosensitizers and co-catalysts, so the efficient passivation of interface defects can enhance their photocatalytic performance. In this work, P-doped C₃N₄ (P−C₃N₄) was prepared by the thermal polymerization of urea with phytic acid as the P doping source. Then, the doped P atoms could act as anchoring sites for photodeposited Ni nanoparticles (NPs) on P−C₃N₄, and Ni−P−N bonds were spontaneously formed between Ni NPs and P−C₃N₄ with doped P as the bridging ligand. The optimal H₂ evolution rate of P−C₃N₄/Ni-20 is 1.56 mmol g⁻¹ h⁻¹, which is 52.0 and 6.0 times that of C₃N₄ and C₃N₄/Ni-30, respectively, and even 2.0 times that of P−C₃N₄/Pt-2%. Its apparent quantum efficiency of 4.35% at 420 nm was 6.9 times that of reference C₃N₄/Ni-30 without P doping.