Self-Lubricating Tribo-Catalytic Activity of 2D High Entropy Alloy Nanoflakes.

High Entropy Alloys (HEAs) have garnered attention due to their remarkable tribological attributes. Predominantly, failure mechanisms in HEAs emanate from stress-induced dislocations, culminating in crack propagation and film delamination. In this study, we report on the synthesis of 2D HEA of (MoWNbTaV)S which facilitates shear-induced energy dissipation at sliding interfaces. The ball-on-disk tribological investigations demonstrate unprecedentedly low average coefficients of friction (0.076) and wear rates (10 mm (N∙m)) under high contact pressures (0.936 GPa) within ambient conditions. Employing multi-scale characterizations alongside molecular dynamic simulations, we elucidate that the presence of the HEA triggers tribocatalytic activity under high contact pressures emerging as a pivotal factor in extending lubricant lifespan during tribological tests. The resilient lubriciousness coupled with the facile spray coating methodology of (MoWNbTaV)S in ambient environments paves the way for the development of a new class of solid lubricants based on 2D HEA.