Synergistic lubrication of MoS 2 quantum dot-reinforced DLC coatings by self-adaptive debris and in-situ tribofilm

Abstract A tribological system was established using diamond-like carbon (DLC) as both friction pairs, and a solid–liquid composite lubrication strategy was introduced by incorporating molybdenum disulfide quantum dots (MoS 2 QDs) into polyethylene glycol 200 (PEG 200). Under DLC/DLC contact, MoS 2 QDs-PEG200 reduced the wear volume by 35.9% compared with PEG 200 alone. The underlying mechanism is attributed to the morphological evolution of wear debris, which transformed from lamellar to blocky and eventually to curly strip-like structures in response to sliding motion. Concurrently, a MoS 2 QDs-enriched tribofilm formed at the contact interface, cooperating with the adaptive debris to provide durable friction reduction and enhanced wear resistance. These findings highlight the potential of MoS 2 QDs-enhanced lubricant for reliable protection of DLC-based components in advanced engineering applications.