Exploring Reduction Techniques for Graphene Oxide: A Comparative Study of Thermal and Chemical Methods

Abstract

Graphene oxide (GO) is a single layer of carbon atoms obtained from the oxidation of graphite by the modified Hummers' method. Sulfuric acid acts as an intercalating agent and allows potassium permanganate to enter the layers to oxidize each layer of graphite to form GO. The resultant GO is highly hydrophilic and less conductive in nature. We further reduced it using a combination of thermal and chemical methods. Thermally reduced GO has been produced by thermal treatment of GO, and chemically reduced GO was obtained by two different reducing agents, such as l-ascorbic acid and sodium borohydride. The degree of oxidation and the purity of the RGO were analyzed using Fourier transform infrared (FTIR), Raman spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). FTIR analysis of GO revealed distinct absorption peaks of oxygen-based functional groups that show a higher degree of oxidation of the carbon structure. Upon reduction, the FTIR spectrum exhibits a partial or total removal of the same, which signifies the loss of oxygen and the partial restoration of the graphitic structure. The results emphasize that the carbon-to-oxygen ratio was higher in both reduction methods, but thermal reduction yielded a greater degree of deoxygenation than the other.