Bi-directional evolution of graphenic vacancy structure in oxygen plasma treatment

The phenomenon of friction increase in graphenic materials during prolonged treatment in an oxygen plasma environment has been widely recognized. In this study, we report a possible oxidation state that leads to decreased friction during oxygen plasma treatment of graphenic materials through molecular simulations. We also propose a simple, clean, and efficient method to control the reverse structural evolution for controlled oxidation. Experimental applications demonstrated a 30.6 % reduction in friction and a 130.1 % increase in friction for short and long oxygen plasma treatments, respectively, compared to the initial graphenic vacancy structure. These findings contribute to an increased understanding of the response and modulation of graphenic coatings in oxygen plasma environments. © 2025 Elsevier Ltd