Macroscale structural superlubricity: Dynamic evolution of tribolayers in two-dimensional materials under extreme pressure

Achieving macroscale structural superlubricity with two-dimensional (2D) materials under ultrahigh contact pressure in ambient condition is particularly challenging. Furthermore, the mechanisms underlying the disparate trans-scale tribological behaviors of 2D materials continue to be a subject of debate. Here, we propose a novel principle concerning pressure-induced dynamic structural evolution and tribochemical behaviors of tribolayers to broaden the macroscale structural superlubricity. For the first time, robust macroscale structural superlubricity with ultralow wear rate is realized by 2D material coating in ambient condition by sliding steel counterparts under ultrahigh contact pressure. The results reveal that macroscale structural superlubricity of 2D materials is highly dependent on the dynamic evolution of tribolayers nanostructures, as well as the adsorption and tribochemical behaviors governed by extreme pressure. These findings shed light on achieving robust macroscale structural superlubricity with 2D materials for harsh engineering conditions.