Activation engineering on metallic 1T-MoS2 by constructing In-plane heterostructure for efficient hydrogen generation

The metallic polymorph of molybdenum disulfide (1T-MoS2) is a promising catalyst towards the hydrogen evolution reaction (HER). However, the intrinsic activity on basal plane is significantly inferior to that at edges despite the dominate number of basal plane atoms. Herein, we conducted an activation engineering to enhance the catalytic activity of the basal plane by constructing in-plane heterostructure with CoS2 nanodomains embedded in 1T-MoS2 basal plane (CoS2@1T-MoS2). Experimental and DFT analysis demonstrates a charge transfer from both CoS2 and 1T-MoS2 to the interface, which enables the formation of electron rich sites with high activity. Moreover, the in-plane heterostructure fully exposes the heterogeneous interfaces and promotes the accessibility of active sites. Consequently, the CoS2@1T-MoS2 delivers an excellent performance towards the HER with an overpotential of 72 mV at 10 mA·cm−2, Tafel slope of 45 mV·dec−1 as well as remarkable stability. This work proposes a strategy to design highly efficient electrocatalysts based on 1T-MoS2.