Nickel-iron phosphides nanorods derived from bimetallic-organic frameworks for hydrogen evolution reaction

It is impending but still a big challenge to design and synthesize electrocatalyst with typical nanostructure and efficient catalytic activity for hydrogen evolution reaction (HER). Herein, we report a low-temperature phosphorization process to synthesize nickel-iron bimetallic phosphides (NiFeP) using MIL-88-Fe2Ni MOF (metal-organic framework) as precursor. The as-synthesized NiFeP shows superior electrocatalytic performance with lower onset overpotential, smaller Tafel slope, bigger exchange current density and lower overpotential to reach the current density of 10 mA cm−2 than both NiP2 and FeP for HER in alkaline solution. The enhanced electrochemical activity may be attributed to the existence of the synergistic effect between NiP2 and FeP. SEM and TEM images show that the obtained NiFeP bimetallic phosphides preserve the size and morphology of the parent MIL-88-Fe2Ni MOF. And the prominent and stable performance of NiFeP nanorods for HER may also ascribes to the typical rod-like nanostructure with large specific surface area.