Investigating the Reduction/Oxidation Reversibility of Graphene Oxide for Photocatalytic Applications.

The aim of the study was to analyze the reversibility of the cycle of graphene oxide (GO), reduced GO, and GO obtained by consecutive reoxidation of reduced GO. Accordingly, GO was heated in three different atmospheres (oxidizing, inert, and reducing, i.e., air, nitrogen, and argon/hydrogen mixture, respectively) at 400 °C to obtain reduced GO with varying composition. The bare GO and the RGO samples were oxidized or reoxidized with HNO 3 . The thermal properties, composition, bonds, and structure of the samples were investigated with TG/DTA, EDX, Raman spectroscopy, and XRD. Their photocatalytic activity was tested by decomposing methyl orange dye under UV light irradiation.