Fabrication of MBT-functionalized carbon nanosheets as high-performance nanoadditives for enhanced tribological performance

Metal-organic frameworks (MOFs) and their derivatives have recently garnered significant attention due to their structural tunability and unique porous characteristics. In this paper, nitrogen-doped porous carbon nanosheets (N@PCNs) were synthesized using Cu-MOFs as templates through an etching process followed by high-temperature carbonization. Subsequently, the N@PCNs with highly porous structures were employed as carriers to load 2-mercaptobenzothiazole (MBT), forming MBT-functionalized carbon nanosheets (MBT-N@PCNs). Tribological evaluations demonstrated that incorporating only 0.10 wt% MBT-N@PCNs significantly enhanced the lubrication properties of the 500SN. Specifically, the mean coefficient of friction was reduced to approximately 0.1, wear volume decreased by 85.4 %, the extreme pressure load-bearing capacity improved by more than sevenfold, and the thermal stability was notably enhanced. These improved lubrication properties mainly stems from the synergistic effect between MBT molecules and carbon nanosheets, which collaboratively form a robust and effective protective tribo-film on friction surfaces, thereby significantly reducing friction and wear.