Achieving near-zero wear on the surface of DLC coatings with GO@Ce-MOF solid–liquid composite superlubrication system

The development of advanced lubrication technologies is essential for enhancing energy efficiency, reducing environmental impact, and improving mechanical durability. In this study, a high-performance lubrication system tailored for diamond-like carbon (DLC) coatings is designed, employing graphene oxide-functionalized cerium-based metal–organic framework (GO@Ce-MOF) composites as nano-additive in an aqueous polyethylene glycol (PEG) solution. The GO@Ce-MOF hybrids were synthesized via electrostatic self-assembly, demonstrating outstanding tribological characteristics with an exceptionally low coefficient of friction (COF ≈ 0.004) and minimal wear on DLC substrates. Post-friction analysis confirmed that the structural integrity of the DLC coating remained unimpaired, with wear predominantly localized on the opposing steel balls. A bilayer tribofilm, approximately 45.5 nm thick and composed of metal oxides and amorphous carbon, formed on the steel surface, facilitating a transition to carbon/carbon friction interfaces. The rod-like architecture of the cerium-based metal–organic framework (Ce-MOF), encapsulated by layered graphene oxide (GO), synergistically contributed to reduced rolling friction and provided carbonaceous precursors for in situ tribofilm formation. This solid–liquid lubrication synergy enabled superlubricity and near-zero wear. The findings demonstrate a novel strategy for promoting in situ growth of carbonaceous tribofilms on dual friction interfaces, offering transformative potential for sustainable lubrication of advanced coating materials.