Tribological properties of graphene quantum dot hybrid polyethylene glycol lubricated molybdenum disulfide films

Herein, molybdenum disulfide (MoS2) films were obtained by magnetron sputtering, and graphene quantum dots (GQDs) prepared by the hydrothermal method were used as additives for polyethylene glycol (PEG) lubricants to investigate the tribological mechanisms under solid-liquid composite lubrication. The friction coefficient of GQDs hybridized PEG lubricated MoS2 solid-liquid composite films was reduced by 69.23%, and the wear rate was reduced by 79.31% as compared to solid lubrication (MoS2 film). This solid-liquid complex lubrication occurs mainly as abrasive wear. GQDs form a uniform and dense amorphous carbon film on the corresponding balls to protect the wear between the friction pair. This work demonstrates the great potential of zerodimensional and two-dimensional materials for solid-liquid composite lubrication.