V-Doping Strategy Induces the Construction of the Functionally Complementary Ru2P/V-RuP4 Heterostructures to Achieve Amperometric Current Density for HER

It is a great challenge to induce the formation of the RuP 4 phase and realize the construction of a metal-rich phase/phosphorus-rich phase-ruthenium phosphide heterostructure by directional regulation of the proportion of P and metal atoms. The ultra-high conductivity of Ru 2 P and the excellent ability of V-doped RuP 4 to absorb/desorb H* are confirmed by density functional theory (DFT) calculations, which laid a theoretical foundation for the construction of a unique Ru 2 P/V-RuP 4 structure to accelerate HER reaction kinetics. This work innovatively uses the V-doping strategy to induce the formation of RuP 4 phase with high intrinsic activity, and finally construct V-Ru x P y nanosheets with rich Ru/Ru 2 P/V-RuP 4 heterostructures. Thanks to the rich Ru/Ru 2 P/V-RuP 4 heterostructure and the optimization of V dopants, the V-Ru x P y catalyst only needs 180 mV to obtain an industrial-grade current density of 1 A cm −2 . In summary, this work provides a new idea for the design and performance optimization of ruthenium-based catalysts.