Monodispersed and well-dispersed RhxP nanoparticles decorated on phosphorus-doped nitride carbon for efficient alkaline and acidic hydrogen evolution

Metal phosphides (MPs) synthesized by solid-state reaction have shown considerable potential in hydrogen evolution reaction (HER) from water splitting compared with that of Pt. However, large-sized MP nanoparticles (NPs) with irregular morphologies are inevitably achieved via the solid-state reaction with high-temperature calcination, which lead to the reduced availability of the active sites. Here, a simple and straightforward strategy was developed to synthesize monodispersed, uniformly distributed, and small Rh x P NPs decorated on phosphorus-doped nitride carbon (PNC) via the pyrolysis of rhodium(Ш) chloride, triphenylphosphine , and melamine (Rh x P/PNC-m). The Rh x P/PNC-m that served as a HER electrocatalyst displayed excellent performance with the overpotentials of 24 and 27 mV at 10 mA cm −2 in basic and acidic solutions, respectively. This catalyst also showed good long-term stability in both media. The high-performance of Rh x P/PNC-m should be attributed to the small, monodispersed, and highly distributed Rh x P NPs on PNC support, which can supply abundant catalytically active sites for HER. The developed strategy for the synthesis of small Rh x P NPs may offer new opportunities toward the electrochemical applications of other metal phosphides.