Mixed-Metal-Organic Framework Self-Template Synthesis of Porous Hybrid Oxyphosphides for Efficient Oxygen Evolution Reaction.

Developing an efficient, stable yet cost-effective electrocatalyst is the key link along the path to hydrogen fuels produced by water splitting. The current bottleneck in the water electrolysis technology is the sluggish oxygen-evolving reaction (OER) which is also central to the rechargeable metal-air batteries. Herein, we report a promising mixed-metal-organic framework (MMOF) self-template strategy to synthesize CoFe hybrid oxyphosphides with highly porous morphology. Aided by the porous hybrid bulk structure beneficial to fast-ion diffusion to abundant highly active sites, the as-synthesized CoFePO exhibited excellent electrocatalytic activity toward OER, with an overpotential of 291 mV at 10 mA cm and a low Tafel slope of 85 mV dec. With the underpinnings of MMOF maintaining the structural rigidity and stability, the material also showed long life for OER without  discernible activity decay.