Ruthenium-doped metal phosphides with expanded lattices enable efficient alkaline water splitting

Efficient water splitting for renewable hydrogen production requires the development of electrocatalysts with high activity and excellent stability. In this study, multi-metal heterostructures were doped with the precious metal ruthenium (Ru) to prepare advanced electrocatalysts with synergistically enhanced catalytic activity for overall water splitting. Using a sacrificial template, heterostructures with abundant active sites were obtained on nickel foam (NF) by room-temperature impregnation, electrochemical synthesis, and low-temperature phosphorization treatment. Structural characterization and in situ Raman spectroscopy results indicated that Ru doping induced lattice expansion in Ni₂P/Fe₂P, accelerating the dynamic self-reconstruction of the catalyst during electrocatalysis. This enabled the catalyst to autonomously adjust its structure under different voltage conditions, endowing it with superior stability. Electrochemical evaluations revealed the good overall water splitting capability of the Ru-Ni₂P/Fe₂P/NF catalyst, requiring a cell voltage of merely 1.39 V to reach a current density of 10 mA cm^-2. Furthermore, the catalyst exhibited excellent stability and durability. This study highlights the synergistic combination of precious metals and multi-metal heterostructures as a strategy to develop scalable and efficient electrocatalytic platforms.