MXenes, a newly emerging class of layered two dimensional (2D) materials, are promising solid lubricants due to their 2D structure consisting of weakly-bonded layers with a low shear strength and ability to form beneficial tribo-layers. This work aims at evaluating for the first time MXenes lubrication performance and tribofilm formation ability on different metallic substrates (mirror-lapped Fe and Cu discs). After depositing MXenes via ethanol (1 wt%) on the substrates, pronounced differences in the resulting substrate-dependent frictional evolution are observed. While MXenes are capable to reduce friction for both substrates after the full evaporation of ethanol, MXenes lubricating effect on Cu is long-lasting, with a 35-fold increased lifetime compared to Fe. Raman spectra acquired in the wear-tracks of the substrates and counter-bodies reveal notable differences in the friction-induced chemical changes depending on the substrate material. In case of Fe, the progressive failure of MXenes lubrication generates different Fe oxides on both the substrate and the ball, resulting in continuously increasing friction and a poor lubrication effect. For Cu, sliding induces the formation of a Ti₃C₂-based tribofilm on both rubbing surfaces, enabling a long-lasting lubricating effect. This work boosts further experimental and theoretical work on MXenes involved tribo-chemical processes.

MXenes 是一种新兴的层状二维 (2D) 材料，由于其二维结构由弱结合层组成，具有低剪切强度和形成有益摩擦层的能力，因此是很有前途的固体润滑剂。这项工作旨在首次评估 MXenes 在不同金属基底（镜面研磨的铁和铜盘）上的润滑性能和摩擦膜形成能力。通过乙醇 (1 wt%) 将 MXenes 沉积在基板上后，观察到由此产生的基板依赖性摩擦演化的显着差异。虽然 MXenes 能够在乙醇完全蒸发后减少两种基板的摩擦，但 MXenes 对 Cu 的润滑作用是持久的，与 Fe 相比，寿命延长了 35 倍。在基底和对应体的磨损轨迹中获得的拉曼光谱揭示了摩擦引起的化学变化的显着差异，这取决于基底材料。在 Fe 的情况下，MXenes 润滑的渐进失效会在基底和球上产生不同的 Fe 氧化物，导致摩擦不断增加，润滑效果差。对于 Cu，滑动会导致 Ti 的形成_{两个摩擦表面上的3} C ₂基摩擦膜，可实现持久的润滑效果。这项工作促进了 MXenes 涉及摩擦化学过程的进一步实验和理论工作。