Macroscale Superlubricity on Nanoscale Graphene Moiré Structure‐Assembled Surface via Counterface Hydrogen Modulation

Abstract

Abstract Interlayer incommensurateness slippage is an excellent pathway to realize superlubricity of van der Waals materials; however, it is instable and heavily depends on twisted angle and super‐smooth substrate which pose great challenges for the practical application of superlubricity. Here, macroscale superlubricity (0.001) is reported on countless nanoscale graphene moiré structure (GMS)‐assembled surface via counterface hydrogen (H) modulation. The GMS‐assembled surface is formed on grinding balls via sphere‐triggered strain engineering. By the H modulation of counterface diamond‐like carbon (25 at.% H), the wear of GMS‐assembled surface is significantly reduced and a steadily superlubric sliding interface between them is achieved, based on assembly face charge depletion and H‐induced assembly edge weakening. Furthermore, the superlubricity between GMS‐assembled and DLC25 surfaces holds true in wide ranges of normal load (7–11 N), sliding velocity (0.5–27 cm −1s), contact area (0.4×104–3.7×104 µm2), and contact pressure (0.19–1.82 GPa). Atomistic simulations confirm the preferential formation of GMS on a sphere, and demonstrate the superlubricity on GMS‐assembled surface via counterface H modulation. The results provide an efficient tribo‐pairing strategy to achieve robust superlubricity, which is of significance for the engineering application of superlubricity.

Keywords

• counterface hydrogen modulation
• graphene moiré structures
• strain engineering
• superlubricity
• van der Waals