Molybdenum Disulfide-Functionalized Nitrogen-Doped Carbon Nanocomposites as Lubricating Additives with Enhanced Tribological Behavior

In this paper, the molybdenum disulfide (MoS₂) nanosheets were deposited onto hyper-crosslinked polystyrene nanospheres (HPSs) using polydopamine (PDA) as binding agent, followed by carbonization to obtain MoS₂ functionalized nitrogen-doped carbon nanocomposites (MoS₂@N-CNs). The resulting MoS₂@N-CNs demonstrated good dispersion stability and lubrication performance as lubricant additives. When 2.0% of MoS₂@N-CNs was added to base oil 500SN, the friction coefficient was decreased by 42.6%, and wear volume was reduced by 59.1%, while the load-bearing capacity increased from 300 N to 1250 N. MoS₂@N-CNs could effectively fill and repair friction surface (filling and repairing effect) and form a protective film (protective film effect). Combined with the ball-bearing effect, these mechanisms synergistically contributed to achieving good friction reduction and wear resistance.