Heterostructured rGO/MoS2 nanocomposites toward enhancing lubrication function of industrial gear oils

Reduced graphene oxide (rGO)/molybdenum disulfide (MoS 2 ) heterostructure nanosheets (rGO-MoS 2 -1) were synthesized via vertically growing of MoS 2 on rGO skeleton using a facile one-pot hydrothermal method. Toward high-performance lubrication additive, the rGO-MoS 2 -1 in industrial gear oil shows extraordinary dispersity and stability because its steric hindrance effect restrains the aggregation and settling tendency. More importantly, its introduction can significantly reduce the friction (∼16.7%) and wear (up to 80%) under the sliding contact. The characterization and analysis on the worn surfaces reveal that good dispersion stability, the formation of rGO-MoS 2 -based lubrication protective film, and the lower shear strength induced by the inherent lattice mismatch between rGO and MoS 2 are the key factors in the friction reduction and protection the tribo-interfaces against wear.