A highly effective bifunctional catalyst of cobalt selenide nanoparticles embedded nitrogen-doped bamboo-like carbon nanotubes toward hydrogen and oxygen evolution reactions based on metal-organic framework

Abstract Metal selenides as highly efficient bifunctional electrocatalysts were extensively applied to water-splitting technology. In present work, N-doped graphitized carbon wrapped CoSe2 nanoparticles (NPs) with in-situ grown bamboo-like carbon nanotube (CoSe2@N/C-CNT) was successfully synthesized via a Co-Ade (Adenine) MOF-derived selenylation strategy. Each CNT was capped with CoSe2 NP, which not only effectively avoided self-agglomeration of CoSe2 NPs but also protected the CoSe2 NPs from electrolyte etching. The synergism of bamboo-like CNT with high conductivity and the uniformly distributed CoSe2 NPs endowed CoSe2@N/C-CNT the better bifunctional electrocatalytic activities toward both HER (hydrogen evolution reaction) and OER (oxygen evolution reaction). To generate a current density of 10 mA cm−2, CoSe2@N/C-CNT exerted as low as overpotential (η) of 185 mV vs. RHE (reversible hydrogen electrode) and 340 mV vs. RHE for HER and OER, the corresponding Tafel slopes were 98 and 107 mV dec-1 respectively. In addition, CoSe2@N/C-CNT exhibited superior durability with negligible attenuation after long-term stability test.