Rapid oxidation of CVD-grown graphene using mild atmospheric pressure O2 plasma jet

We have developed a low cost and rapid functionalization process, called mild atmospheric pressure plasma jet (MAPPJ), for one-atom-layer thick graphene, which was successfully used to oxidize single layer graphene with oxygen introduction. The plasma damage, which is inevitably suffered in conventional atmospheric pressure plasma jet, can be efficiently inhibited by simply inserting a filter mesh between the plasma jet and the graphene sheet. Raman and X-ray photoelectron spectroscopies revealed that oxidative functionalities were incorporated onto the graphene surface. The quantity of oxidative functionalities reached 24.1% within 15 s. Contact angle measurements also demonstrated that the high hydrophilicity of the oxidized graphene sheet resulted from the existence of oxidative groups formed by MAPPJ.