Degradation of Methyl Red under Visible Light Using N,F-TiO2/SiO2/rGO Nanocomposite

Abstract

N,F-TiO2 and SiO2 nanoparticles have been synthesized by a sol–gel method and grown on reduced graphene oxide by a solvothermal method at different molar ratios. The microstructure and morphology of the N,F-TiO2/SiO2/rGO nanocomposite were investigated by Fourier-transform infrared spectroscopy, x-ray diffraction analysis, field-emission scanning electron microscopy, transmission electron microscopy, energy-dispersive x-ray spectroscopy, and Brunauer–Emmett–Teller surface area (SBET) measurements. The synthesized nanocomposite was used for photocatalytic degradation of Methyl Red (MR) dye. Ultraviolet–visible (UV–Vis) spectrophotometry was used to determine the degree of dye degradation before and after contact with the nanocomposite, and the absorbance was measured at 518 nm. The results confirmed that the N,F-TiO2/SiO2/rGO nanocomposite degraded 95% of MR after 60 min under visible-light irradiation. Factors affecting its photocatalytic ability were investigated and optimized. The results showed that the highest degradation efficiency was observed when 1.5 mL silica sol was used to synthesize the nanocomposite. Finally, the mechanism of Methyl Red degradation was investigated.