Surface engineering of graphene oxide using Glyceline deep eutectic solvent: Structural, morphological, and electrochemical studies

Graphene is an allotrope of carbon atoms in a 2D-shape. It has extraordinary mechanical, physicochemical, and electrochemical characteristics. However, it possesses lack of dispersion in some solvents like water. In order to overcome this problem the graphene nanosheets are oxidized and functionalized in order to attach to functional groups which are hydrophilic. So far, many works have been done such as functionalization with biomolecules such as amino acids. Due to problems such as handling some organic solvents during the functionalization we have proposed a safe approach which is very simple and less effort is required. Functionalization of graphene oxide (GO) with deep eutectic solvents can be a more convenient alternative to previous materials. During this work the graphene oxide nanosheets have been modified with a new generation of ionic liquids called deep eutectic solvents (DES). The DES has been synthesized from a hydrogen bond donor (HBD) glycerine and hydrogen bond acceptor (HBA) choline chloride. Then the DES has been applied to GO and different physicochemical and electrochemical analyses have been conducted in order to verify the validity of the work. The functionalized GO has been characterized with FTIR, BET and BJH, FESEM, EDS and Cyclic voltammetry (CV) techniques. The results from the analyses show considerable improvement in the GO nano-layers after the functionalization with the DES. The obtained data from CV analysis show the enhancements in the area of the electroactive materials and specific capacitance of the modified GO. The GO-modified with DES can be used in different areas, particularly in energy storage capacitors.