Anchoring Carbon-Based Quantum Dots on MoS 2 Nanosheets Achieves Fast Running-In and Stable Low-Friction Behavior under Liquid Conditions

To address issues such as prolonged break-in periods, high initial friction, and severe wear in high-load liquid lubrication systems, this study successfully synthesized a composite lubricant additive (CDs@MoS 2 ) composed of zero-dimensional carbon-based quantum dots (CDs) and two-dimensional molybdenum disulfide (MoS 2 ) nanosheets via an ionic liquids (ILs)-assisted hydrothermal strategy. This composite exhibits rapid run-in and stable low-friction properties in liquid media. Compared to pure water and PAO10 base oil, its average coefficient of friction decreased significantly by 79% and 84%, respectively, while the run-in period was reduced to under 60 s. Surface analysis reveals spherical CDs acting as nano “ball bearings” effectively fill surface microgrooves and reduce shear stress. Layered MoS 2 provides low-shear slip pathways and accelerates its spreading effect at the coupling interface. This synergistic action promotes the formation of a continuous, dense tribofilm, enabling rapid run-in and low friction. This study offers a novel design approach for constructing high-performance 0D/2D synergistic lubrication systems, providing valuable insights for developing environmentally friendly liquid lubrication systems with short break-in periods and high stability.