MOF-derived highly active Ni/Co/NC electrocatalyst and its application for hydrogen evolution reaction

摘要

The development of electrocatalysts with excellent activity for clean and sustainable H-2 has been considered as an efficient way to store energy and meet the increasing energy and environmental demands. In this paper, we used zeolitic imidazolate frameworks-67 (ZIF-67) as precursors to synthesize the highly active N-doped graphene loaded with Ni and Co nanoparticles (Ni/Co/NC) for hydrogen evolution reaction (HER). The physical and electrochemical characterization of all synthesized samples were analyzed by X-ray diffraction, Raman spectra, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and HER. The results show that the organic ligands of ZIF-67 were successfully transformed into N-doped graphene after high temperature treatment. Ni element was well dispersed in the supporting graphene and can make the graphene keeping the dodecahedral morphology with hollow structure. Co nanoparticles were encapsulated by a layer of graphene. Electrochemical tests show that Ni/Co/NC800 exhibits excellent performance for hydrogen generation: the onset overpotential is only 125 mV, the Tafel slope is 57.6 mV/dec. The excellent performance of Ni/Co/NC800 makes its being a promising candidate for energy storage and conversion applications.