Facile synthesis of CoFeP microcubes derived from metal-organic frameworks for efficient oxygen evolution reaction.

The electrochemical splitting of water provides an attractive method for the production of hydrogen fuels. Unfortunately, the slow kinetics of oxygen evolution (OER) on the anode side of the electrolyzer hinders the efficient and large-scale hydrogen production. In this study, starting from metal-organic frameworks (MOFs), a series of bimetal phosphides CoFeP (x = 0.33, 0.50, 0.66, 0.75 and 0.80) were synthesized by low-temperature phosphidiation of corresponding MOFs precursors. The as-prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Studies indicate that the proportion of cobalt and iron elements make a big differences on the structure of the materials. Benefiting from the porous structure and large specific area of the MOFs precursors, as well as the synergistic effect between Co and Fe elements, the as-synthesized CoFeP shows superior electrocatalytic performances and outstanding stability toward OER in alkaline solution.