Recent progress in transition metal dichalcogenides as advanced lubricants: Mechanisms, modulation strategies, and applications

The persistent economic and environmental challenges arising from friction-induced energy losses underscore the critical need for innovative lubrication technologies. Two-dimensional transition metal dichalcogenides (2D TMDs), characterized by their layered architecture and weak interlayer van der Waals (vdW) interactions, have emerged as promising nanolubricants due to their well-documented shear properties and ability to form low-friction tribofilms. However, practical applications of TMDs are hindered by inherent limitations, including insufficient load-bearing capacity and high sensitivity to environmental conditions. Accordingly, extensive research efforts have been directed toward the rational design and structural modification of TMD-based lubricants. This review outlines recent advances in TMD-based tribological systems, beginning with their structural characteristics and synthesis routes, followed by an in-depth discussion of lubrication mechanisms and key performance-influencing factors. Moreover, this review explores modulation strategies for TMD-based lubricants, from conventional methods to emerging approaches, along with their applications in diverse environments. Finally, this review identifies prevailing challenges and suggests promising research directions to guide the development of next-generation high-performance TMD-based lubricants.