Effect of the oxidation degree on the bandgap of graphene oxides by Tour method

In this work graphene oxides (GOs) were synthesized by the tour method. The oxidation degree of GOs was varied using different dosages of KMnO4 during the synthesis (0.5, 3, and 6 g). By X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), we quantitatively determined the oxidation degree of the materials (4.1, 49.5, and 53.9%). In addition, bandgaps ranging from 0.8 to 2.18 eV were calculated, thus verifying the dependence of the bandgap on the oxidation degree. With this work, we demonstrate that by the tour method it is possible to synthesize and control the oxidation degree in the GOs, in such a way that we can change the nature of the material from semimetallic to semiconducting with the modification of its bandgap. The study of our GOs was complemented with FT-IR spectroscopy and Raman spectroscopy.