Graphene Mitigates Nanoscale Tribochemical Wear of Silica Glass in Water

Despite the ubiquitous use of glasses, their simultaneous susceptibility toward scratch-induced defects and atmospheric hydration deteriorates their mechanical and chemical durability. Here, it is demonstrated that the deposition of a few-layer graphene provides unprecedented wear resistance to silica glass in aqueous conditions. To this extent, nanoscale scratch tests are carried out on graphene-glass surfaces via contact-mode atomic force microscopy with chemically inert and reactive tips. It is observed that the graphene-glass exhibits up to ≈98% friction reduction and no discernable damage or material loss. This observation is in stark contrast to the behavior of bare silica glass which suffers severe tribochemical wear at equivalent contact conditions with even milder stresses. Further, through reactive molecular simulations, it is demonstrated that parallel mechanisms of lubrication and chemical passivity contribute to the enhanced damage resistance of graphene-glass surfaces against any countersurface chemistry. Altogether, the present study provides an impetus toward physically and chemically durable glass coatings exploiting the functionalities of two-dimensional materials.