Atomic Scale Simulation on the Anti-Pressure and Friction Reduction Mechanisms of MoS₂ Monolayer

MoS₂ nanosheets can be used as solid lubricants or additives of lubricating oils to reduce friction and resist wear. However, the atomic scale mechanism still needs to be illustrated. Herein, molecular simulations on the indentation and scratching process of MoS₂ monolayer supported by Pt(111) surface were conducted to study the anti-pressure and friction reduction mechanisms of the MoS₂ monolayer. Three deformation stages of Pt-supported MoS₂ monolayer were found during the indentation process: elastic deformation, plastic deformation and finally, complete rupture. The MoS₂ monolayer showed an excellent friction reduction effect at the first two stages, as a result of enhanced load bearing capacity and reduced deformation degree of the substrate. Unlike graphene, rupture of the Pt-supported MoS₂ monolayer was related primarily to out-of-plane compression of the monolayer. These results provide a new insight into the relationship between the mechanical properties and lubrication properties of 2D materials.