Bimetallic Phosphides as High-Efficient Electrocatalysts for Hydrogen Generation.

Bimetallic transition-metal phosphides are gradually evolving as efficient hydrogen evolution catalysts. In this study, graphene-coated MoP and bimetallic phosphide (MoNiP) nanoparticles (MoP/MoNiP@C) were synthesized via one-step straightforward high-temperature calcination and phosphating process. The precursor was obtained from polyaniline, Ni2+ ions, and phosphomolybdic acid hydrate (PMo12) by solvent evaporation. As expected, MoP/MoNiP@C manifests excellent hydrogen evolution activity with a low overpotential of 134 mV at 10 mA cm-2 and a small Tafel slope of 66 mV dec-1. Furthermore, MoP/MoNiP@C exhibits satisfactory stability for 24 h in the acid electrolyte. The outstanding catalytic performance can be attributed to the synergistic effect of MoP and MoNiP nanoparticles, the graphene coating protecting MoP and MoNiP from corrosion, as well as an increase in the number of active sites because of porous structures. This work can provide the experimental foundation for the simple synthesis of bimetallic phosphates with remarkable hydrogen evolution performance.