Fabrication of TiO2 Reduced Graphene Oxide Based Nanocomposites for Effective of Photocatalytic Decolorization of Dye Effluent

Abstract

Reduced graphene oxide (RGO) were successfully prepared through chemical reduction of GO that was prepared by modified Hummer’s method. Characterization of GO and RGO was performed using different techniques and they were trapped in acrylic acid (PAAc) and polyvinyl alcohol (PVA) to form (PVA/PAAc)–GO and (PVA/PAAc)–RGO nanocomposites using gamma irradiation technique. Characterization the prepared nanocomposite was investigated using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and transmission electron microscopy (TEM). TiO2 was also trapped in the nanocomposite matrix to perform (PVA/PAAc)–GO–TiO2 and (PVA/PAAc)–RGO–TiO2 nanocomposite hydrogels. It was found that the crystallite size of (PVA/PAAc)–TiO2, (PVA/PAAc)–GO–TiO2 and (PVA/PAAc)–RGO–TiO2 nanocomposite calculated using Debye–Scherrer’s equation are 52.8, 26.02, and 23 nm, respectively. The surface morphology explained a good dispersion of GO within (PVA/PAAc)–GO–TiO2 and (PVA/PAAc)–RGO–TiO2 appears as a porous structure. The photocatalytic activity of the obtained nanocomposites was tested for the photodecolorization of direct blue 71 dye (DB71) in the aqueous medium under UV light. A complete decolorization of DB71 was achieved after 40 min at pH 6 in the presence of 2 mL/L hydrogen peroxide. The rate of photodecolorization follows Langmuir Hinshelwood pseudo-first-order kinetics. It was also obtained that (PVA/PAAc)–RGO–TiO2 nanocomposites can be reused for ten times with full activity.