Hydrothermal-assisted shearing exfoliation for few-layered MoS₂ nanosheets

The exfoliation of bulk MoS₂ into few layers has attracted considerable attention as 2D nanomaterials in the past decade. We developed a facile approach for producing MoS₂ nanosheets by hydrothermal-assisted shearing exfoliation based on organic-free strategy. This original exfoliation was highly efficient for large-scale production and sustainable for the environment. The thickness of the as-exfoliated MoS₂ nanosheets was about 4-6 layers, and the lateral size became smaller from hydrothermal processing to shearing. The hydrothermal processing with the participation of ammonium carbonate played an important role in hydrothermal-assisted shearing exfoliation. As a prospective application, the antifriction performance of the as-exfoliated MoS₂ nanosheets in oil was evaluated using a ball-on-ball mode. Evidently, the average friction coefficient and wear scar diameter of 0.08 wt% MoS₂-based oil dropped to about 20.66% and 47.27% relative to those of the base oil, which exhibited an excellent antifriction and antiwear ability.