Effect of nickel phosphide nanoparticles crystallization on hydrogen evolution reaction catalytic performance

In order to investigate the effect of nickel phosphide nanoparticles' (Ni-P NPs) crystallization on hydrogen evolution reaction (HER) catalytic performance, amorphous Ni-P NPs and crystalline Ni12P5 were synthesized by a simple and low-cost autocatalytic reduction method and heat treatment process. The result of electrochemical tests shows that crystalline Ni12P5 has much higher HER catalytic activity than the amorphous one. X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy revealed that Ni-P bond formed during crystallization, making Ni positively charged and P negatively charged. This charged nature of Ni12P5 is similar to [NiFe] hydrogenase and its analogous, which make the removal of H2 less energy-cost.