Kinetics of Photocatalytic Degradation of Methylene Blue by TiO2-Graphene Nanocomposites

Reduced graphene oxide (RGO)/TiO2 nanocomposite was successfully prepared by UV-assisted photocatalytic reduction of graphene oxide (XGO) by TiO2 nanoparticles in ethanol. The effects of XGO and RGO addition in TiO2 were characterized by transmission electron microscopy (TEM), X-ray diffractometer (XRD), diffuse reflectance UV vis spectrophotometer (UV vis), fourier-transform infrared spectroscopy (FTIR), photoluminescence (PL), and Brunauer-Emmett-Teller (BET) and Barrett-Joiner-Halenda (BJH) porosity analysis. The photocatalytic activity of prepared nanocomposites was evaluated from the kinetics of the photocatalytic degradation of cationic methylene blue dye under UV irradiation. Bandgap, the electron hole recombination, specific surface area, surface functional groups, and adsorption capacity of nanocomposites were found to play a significant role in the degradation. The results revealed that RGO/TiO2 and XGO/TiO2 nanocomposites exhibited efficient charge separation and enhanced photocatalytic activity, compared to pristine TiO2. Nearly 500% improvement was observed in this work.