Finely tuning oxygen functional groups of graphene materials and optimizing oxygen levels for capacitors

Oxygen-containing, chemically modified graphene (CMG) systems have been intensively investigated for various applications. The development of methods that allow fine control of the oxygen functionality would help better understand the mechanisms associated with CMGs, facilitate optimization of the material properties, and provide standards for chemical characterization purposes. Here, the authors report a new method for finely controlling the levels of oxygen in CMG materials based on the refluxing of aqueous colloidal suspensions of graphene oxide for specific reflux times, which does not require additional reducing agents. Chemical analysis confirmed that the oxygen levels can be finely controlled and they can provide spectroscopic tools to monitor the oxygen levels of CMG-based systems. This system was applied to help provide a fundamental foundation for the correlation between the oxygen groups and capacitive features.