CoSe2 nanoparticles embedded MOF-derived Co-N-C nanoflake arrays as efficient and stable electrocatalyst for hydrogen evolution reaction

It is still challenging to develop highly efficient and stable non-noble metal-based electrocatalysts for hydrogen evolution reaction (HER). Herein, CoSe2 nanoparticles embedded Co-N-doped carbon nanoflake arrays (CS@CNC NAs) are grown on carbon cloth (CC) through a co-precipitation and annealing process. The CS@CNC NAs/CC hybrid electrocatalyst shows superior HER performance with a small Tafel slope of 38 mV dec(-1), an ultralow overpotential of 84 mV at 10 mA cm(-2) and an excellent long-term stability with nearly no decay even after 72 h. The outstanding HER performance of CS@CNC NAs/CC is mainly attributed to the synergetic effects of CoSe2 nanoparticles and CNC nanoflake arrays, which can not only provide rich active sites, easy access of electrolyte and diffusion of H-2 bubbles, but also guarantee its high conductivity and structural stability. This work provides a novel strategy for the rational fabrication of highly effective and stable transition metal selenide-based electrocatalysts for HER.