MOF-based bimetallic diselenide nanospheres as a bifunctional efficient electrocatalysts for overall water splitting

The synthesis of an economical and efficient bifunctional electrocatalyst for general water splitting is necessary for the fabrication of eco-friendly H 2 energy. Herein, state-of-the-art ZIF-67-based CoSe/MoSe 2 hybrid nanospheres were synthesized and examined as a bifunctional electrocatalyst for Hydrogen evolution reaction (HER) and Oxygen evolution (OER) in basic media. For the first time, a hierarchical well-designed CoSe/MoSe 2 hybrid nanospheres designed with the uniform distribution layered of 2D-MoSe 2 and conductive CoSe nanoparticles are acquired from CoMoO 4 via selenization. Due to its large surface area and extraordinary morphology, it exhibited significant catalytic activity, which leads to a small overpotential of 110 mV for HER and for 240 mV OER along with low Tafel values of 54.24 and 51.98 mV dec −1 , respectively. Surprisingly, the stability is marvelous and also comparable to the standard of HER and OER. The enhancement is endorsed by the increase in conductivity evolved from the porous nanospheres and the collaborative effect of Co/Mo. To deliver a current density of 10 mA per cm 2 for full water splitting 1.56 V is required, which is one of the least reported voltages. Therefore, this work leads to a new class of catalysts for the fabrication of an efficient water electrolyzer.