Sea urchin-like CoSe2 nanoparticles modified graphene oxide as an efficient and stable hydrogen evolution catalyst

Abstract

• We demonstrated a simple green route to sea urchin-like CoSe 2 nanoparticles. • CoSe 2 were fixed on graphene oxide sheet to form CoSe 2 /GO conductive network. • CSGN-30 shows good catalytic activity and stability in the HER reaction. Catalysts for hydrogen evolution are at the heart of renewable energy, but developing low-cost, highly active electrocatalysts remains a huge challenge. In this study, ascorbic acid was used for the first time to synthesize sea urchin-like CoSe 2 nanoparticles by a simple and convenient hydrothermal method. Then the CoSe 2 was fixed on the graphene oxide (GO) nanosheets with few layers to form a CoSe 2 /GO conductive network (CSGN). It was found that the doping with different amounts of graphene oxide can make CoSe 2 exhibit different HER catalytic activities. When the Tafel slope of CSGN-30 is 38.2 mV/dec, the doping amount of the corresponding GO is 30 mg, which was lower than immaculate CoSe 2 (98 mV/dec) and most of the detailed CoSe 2 or NiSe 2 based catalysts. Compared with pure CoSe 2 , CSGN-30 shows faster energy and superior electrocatalytic movement in hydrogen evolution reaction. CSGN-30 provides a current density of 10 mA/cm 2 at 184 mV overpotential, which is much smaller than pure CoSe 2 (308 mV). Even after 1500 CV cycles, CSGN-30 still shows good cycle stability. The fabulous HER performance of CSGN is credited to its graphene high conductivity, which makes the catalyst possesses high electrochemical active surface area as well as the efficient charge transfer between the electrocatalyst and the electrolyte. This work not only gives thoughts for the preparation of metal chalcogenides, but also gives modern bits of knowledge for the planning of hydrogen advancement catalysts.