Synthesis of ultrafine ruthenium phosphide nanoparticles and nitrogen/phosphorus dual-doped carbon hybrids as advanced electrocatalysts for all-pH hydrogen evolution reaction

Pt-group metal phosphides are widely utilized as efficient electrocatalysts for hydrogen evolution reaction (HER), whereas most of the synthetic strategies are complicated, dangerous, and toxic with the use of large amount of nitrogen (N) and/or phosphorus (P) sources. Here, we report the synthesis of ruthenium phosphide nanoparticles (NPs) confined into N/P dual-doped carbon by pyrolyzing self-prepared ruthenium-organophosphine complex using 1,3,5-triaza-7-phosphadamantane (PTA) as the ligand and N/P sources. The achieved S–RuP2/NPC displayed excellent electrocatalytic activity (overpotentials of 19, 37, and 49 mV in alkaline, neutral, and acidic media, respectively, at 10 mA cm−2) toward HER at all pH ranges. The high performance of S–RuP2/NPC must be ascribed to the homogeneously distributed and P-rich RuP2 NPs with the diameter of 3.29 nm on the NPC surface, which can considerably improve the atom utilization for HER. The present synthetic strategy not only avoids the use of additional N/P sources but also the generation of flammable and toxic PH3 gas. This synthetic strategy can be extended to prepare other traditional metal phosphides for electrocatalytic applications.