Tunable degree of oxidation in graphene oxide: cost effective synthesis, characterization and process optimization

Abstract

Graphene oxide (GO) with various power of oxidation level was fabricated by varying weight of oxidizing agent KMnO4 and oxidation time using modified Hummers method. Functionalities developed on GO were characterized through Fourier transformer infrared spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV), Raman spectroscopy, Thermogravimetric analysis (TGA), Field emission scanning electron microscopy (FE-SEM) and high resolution transmittance electron microscope (HR-TEM) technique. The Raman and FTIR studies confirm 4.5 g KMnO4 as the optimized weight and 4 h as the optimized oxidation time for the GO synthesis. The deviation of a crystalline state towards amorphous is also confirming the variation of oxidation through Raman results. Furthermore, for better applicability, the dispersion behavior of tailored GO with different oxygen functionality was also studied in different polar and non-polar solvents. The fabricated graphene oxide has shown better dispersion in Methanol, Ethanol, DMF, Acetone, Ethylene glycol, and Water. In addition, these dispersed solutions showed long-lasting stability in these solvents as shown in water.