GREEN SYNTHESIS OF GRAPHENE AND ITS FUNCTIONALIZATION USING DES

Abstract

The increasing need for sustainable and environmentally friendly materials has induced the search for ecologically-clean synthesis methods for advanced nanomaterials. This dissertation describes a green synthetic route to graphene with the further modification by Deep Eutectic Solvents (DES). To start with, via a modified Hummers procedure (GO) have been synthesized. This method allows for better control over oxidation levels and particles dispersion properties. Then the GO was reduced by a plant-based phytoextract which is a nontoxic and eco-friendly alternative to conventional chemical reducers. The RGO thus obtained was further characterized by Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible (UV-Vis) spectroscopy, and Thermogravimetric Analysis (TGA) to check the extent of reduction and to evaluate thermal stability. In the next step a DES was prepared by mixing the naturally obtained hydrogen bond donors and acceptors. This DES is then used for the modification of the RGO surface in order to improve its chemical reactivity and application. The functionalized graphene was characterized. The FTIR experiment reveals the nature of the mutual interaction of the DES components and the graphene surface. The results indicate that DES is not only the functionalizing agent but also the stabilizing agent of the graphene sheets phenomenon that can lead to the utilization of green sectors such as chemistry and nanotechnology. This work highlights the possibilities of using green chemistry principles to produce and modify graphene-based materials, thus creating a more environmentally friendly way of conducting research in the field of material science.