Modulating the electronic structure at the interface of CoSe and MoSe2 for enhanced electrocatalytic hydrogen evolution reaction

Metal selenide is a group of promising electrocatalysts for hydrogen evolution reaction (HER). However, Molybdenum selenide (MoSe2) exhibits sluggish HER kinetics in alkaline electrolytes mainly due to inherently inferior electrical conductivity and disappearance of edge active sites. Herein, we reported the preparation of MOF-derived CoSe/MoSe2 heterogeneous structure with excellent electrocatalytic activity in HER. The over potential of CoSe/MoSe2 at current density of 10 mA cm-2 was only 135 mV. DFT calculations and characterization results revealed that the excellent HER electrocatalytic performance was attributed to the fabrication of the CoSe/MoSe2 interface. As-fabricated interface not only improved the electrical conductivity through modulating the electronic structure, but also enhanced H* adsorption thereby alleviating the energy barrier. Moreover, CoSe derived from the ZIF-67 with porous structure can provide the larger surface for the uniform growth of MoSe2 and then expose abundant edge active sites of MoSe2. This work enriched and developed the strategies for the designing of more highly efficient electrocatalysts via the heterogeneous interface modulation.