N, P co-doped graphene-supported monometallic nanoparticles for highly efficient hydrogen evolution by acid electrolysis of water

Pt/rGNP exhibits much higher catalytic properties than other transition metal/rGNP catalysts for hydrogen evolution; its overpotential at 100 mA cm −2 in 0.5 M H 2 SO 4 is only 10.6 mV, and its Tafel slope is 14.53 mV dec −1 .