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