Influence of carbonaceous materials supported nanostructured nickel phosphide as an electrocatalyst for the hydrogen evolution reaction

A promising hydrogen evolution reaction performance is achieved in this work by Ni2P nanoparticles supported on Nitrogen, Sulphur co-doped reduced graphene oxide (N,S-rGO) synthesized via hydrothermal method. The enhanced electrochemical activity of the electrocatalyst can be attributed to the presence of more defect sites in the graphitic carbon as well as the synergistic effect between both N and S co-doped reduced graphene oxide. Ni2P–N, S-rGO showed the comparative intensity ratio ID/IG value of 1.96, which is higher compared to other carbon materials. It shows that the defect was increased when nitrogen and sulphur co-doping occurs on reduced graphene oxide sheets which in turn leads to an increase in both active doping sites and improve conductivity. Ni2P incorporated with N, S-rGO was found to be the best for attaining a current density of 10 mA/cm2 at an overpotential of 179 mV in 0.5 M H2SO4. As well, the Tafel slope of 71 mV/dec confirms that the Ni2P incorporated with N, S-rGO proceeds through the Volmer-Heyrovsky mechanism.