Abstract:Carbon-coated cobalt phosphide (CoP/C) powders were prepared by high temperature pre-annealing and further phosphating using Zeolitic Imidazolate Framework-67 (ZIF-67) and Co(NO3)2∙6H2O as precursor. CoP/C powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the electrocatalytic hydrogen evolution experiments were also carried out. The results show that after calcination at high temperature, the organic components of ZIF-67 are transformed into conductive carbon skeleton, and cobalt ions are transformed into elemental cobalt nanoparticles embedded in the carbon skeleton. After further phosphating, pure phase CoP/C powders are obtained. CoP/C powders exhibit good catalytic activity with an overpotential of 64 mV and a Tafel slope of 66 mV/dec, which maintains high catalytic activity after 15 h for electrocatalytic hydrogen evolution.
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