Ti3C2T X derived layered MXenes as friction and wear reducing additives in lubricating oils: a detailed review

Friction and wear are critical aspects that significantly impact the efficiency and durability of mechanical systems. The demand for improved lubricating oils capable of reducing friction and wear has spurred the exploration of advanced additives. Two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides (MXene), a new class of materials, have emerged as promising additives with exceptional tribological properties. This review paper aims to understand the usability of MXene, specifically the ones derived from Ti₃C₂T_Xas anti-friction and antiwear additives in lubricating oils. An elaborate discussion is presented about the synthesis and characterization techniques employed in the synthesis of Ti₃C₂T_X(MXene), emphasizing their unique structural and surface properties that could contribute to their tribological performance, followed by their influence on the lubricant's tribological properties is thoroughly discussed. The underlying anti-friction and anti-wear mechanisms, their ability to form tribofilms on sliding surfaces, reduce direct metal-to-metal contact, and minimize wear are also highlighted. Additionally, the role of MXene in modifying the lubricant's chemical and physical interactions with sliding surfaces is analyzed. This review also attempts to identify and address the roadblocks hindering the use of Ti₃C₂T_XMXene in lubricating oils, such as their aggregation tendencies, stability under extreme conditions, and potential side effects on lubricant properties along with the tentative strategies to overcome these hurdles. Relevant experimental findings in which Ti₃C₂T_Xderived 2D nano-sheets have been explored as friction and wear-reducing additives in different lubricating oils are critically assessed. Although these MXene are claimed to be highly effective as lubricant additives in lubricating oils owing to their unique properties and versatile chemistry, further research is urgently needed to address the challenges and optimize the formulation and integration of MXene into lubricating oils for practical implementation. This article comprehensively discusses Ti₃C₂T_XMXene as friction and wear-reducing additives in lubricating oils, highlighting the pressing need for further research and the potential for future developments in this field.