What is Graphene Oxide?
Graphene oxide is the state of oxidation of graphite layers separately. (Bianco et al. 2013) Graphene oxide includes some functional groups with a C / O ratio of less than 3 and typically 2. (Bianco et al. 2013) One of the prominent methods for producing high amounts of graphene is the reduction of graphene oxide using various methods with chemical processes from graphite.(Eda et al. 2008). Two main advantages of this method come to the forefront, which can be defined for the availability of environmental production in the cheap graphite raw material, where stable solutions can be prepared if the graphite is hydrophilic.
Due to the fact that GO is easily dispersed in solvents, its dielectric property, its electronic properties can be adjusted, and its superior mechanical properties, its application areas are increasing day after day.
Graphene oxide, which contains various amounts of carbon, oxygen and hydrogen in its structure, has been synthesized by Brodie, Staundenmaier, Offeman and Hummers methods since the early 19th century. These methods are based on the oxidation process of graphite with strong acids and oxidants. The degree of oxidation depends on the method which is used, reaction conditions and the properties of graphite. However, toxic chemicals are used in the graphene oxide (GO) production methods and cause releases of toxic gases. In the Hummers method, graphite is reacted with strong oxidizing agents such as potassium permanganate and concentrated sulfuric acid. After oxidation by Hummers method, epoxy and hydroxyl functional groups settle in graphite structure. Water and oxygen-containing functional groups are introduced between the layers by mixing to establish strong interaction and to remove the layers. Thus, the hydrophobic graphite becomes hydrophilic and scattering of GO.