In-plane intergrowth CoS2/MoS2 nanosheet: Binary metal organic framework evolution and efficient alkaline HER electrocatalysis
Alkaline hydrogen evolution reaction (HER) is an extremely important reaction in energy conversion and electrolytic industry. Pristine MoS2 exhibits poor alkaline HER activity due to weak water adsorption and dissociation ability. Precisely manipulating active water dissociation component to form functional interface with MoS2 would be an effective strategy. Herein, in-plane intergrowth CoS2/MoS2 ultrathin nanosheet is achieved via one-step pyrolytic sulfurization of a small-sized Co/Mo-MOF precursor. The in-plane intergrowth structure produces rich interfaces and modulates the interfacial electronic structure, demonstrating an accelerated water dissociation process. Ultralow overpotentials at both onset (16 mV) and 10 mA cm-2 (75 mV) are obtained, which surpass most top-rated MoS2-based materials and are even proximate to commercial Pt/C (0 mV at onset and 60 mV at 10 mA cm-2). Under a large current density of 400 mA cm-2, the intergrowth nanosheet exhibits a long-term stability, showing a prospect in alkaline water splitting devices.