Graphene oxide is a unique material, a material which can be seen as a single monomolecular layer of graphite with oxygen (containing carboxyl, carbonyl, hydroxyl and epoxide groups’ functionalities). When the electrically insulating GO is reduced, the reduced graphene oxide (rGO) formed resembles graphene but contains residual oxygen and other heteroatoms as well as structural defects. A fabrication procedure for rGO that more closely resembles pristine graphene is an outstanding challenge in the field. Nevertheless, rGO is attractive for use in electronic devices, because it can be made as a thin film from an aqueous dispersion of GO in water and it has moderate conductivity. In addition to being components in electronic devices, GO and rGO have been used in nanocomposite materials, polymer composite materials, energy storage, biomedical applications, catalysis,and as a surfactant with some overlaps between these fields.
GO’s synthesis are based on both many modern procedures and the method first reported by Hummers. This method includes graphite which is oxidized by a solution of potassium permanganate in sulfuric acid. Reduction of GO using hydrazine has been reported. However, hydrazine contains high amount of toxic and with nitrogen heteroatoms, it can potentially functionalize the GO. That is why, alternatives to hydrazine including NaBH4 HI and ascorbic acid among others have been used to reduced GO. Graphene oxide can be reduced as an aqueous solution and a thin film. Reduction methods have been recently reviewed.
Many modern procedures for the synthesis of GO are based on the method first reported by Hummers in which graphite is oxidized by a solution of potassium permanganate in sulfuric acid.Reduction of GO using hydrazine has been reported. However, hydrazine is highly toxic and can potentially functionalize the GO with nitrogen heteroatoms. Because of these issues we have mentioned about, for the reduction of GO, alternatives to hydrazine including NaBH4, ascorbic acid, and HI among others have been used. Reduction methods have been recently reviewed.