Solid Lubrication Performance of Hybrid Ti3C2Tx/MoS2 Coatings

MXenes have gained notable attention in tribology due to their excellent wear resistance based on the formation of beneficial tribofilms. However, studies using MXenes as solid lubricants have mainly focused on multi-layer Ti 3 C 2 T x coatings, while little is known about the tribological performance of MXene composites. Therefore, our study aims at scrutinizing and understanding the tribological behavior of MXenes and MXene composites as solid lubricants under reciprocating sliding conditions. Theoretical predictions regarding the resulting interlayer adhesion and coating-substrate adhesion helped to design the hybrid coatings. Multi-layer Ti 3 C 2 T x , molybdenum disulfide (MoS 2 ) and two hybrid coatings using Ti 3 C 2 T x and MoS 2 (random mixture and sandwich-like) were spray-coated onto steel substrates with a coating thickness of about 800 nm. Dry sliding tests using a steel ball as counter-body were carried out at room temperature. The coatings’ morphology and formed tribofilms were holistically characterized by scanning and transmission electron microscopy (SEM, TEM) as well as X-ray photoelectron spectroscopy (XPS). Our results demonstrated that both hybrid coatings notably reduced friction and wear, which was traced back to synergic effects between Ti 3 C 2 T x and MoS 2 thus enhancing the formation of a stable tribofilm. Consequently, our work demonstrated the potential of Ti 3 C 2 T x /MoS 2 hybrid coatings to further optimize friction and wear.