Synthesis and characterization of TiO2@SiO2–Ag nanocomposites towards photocatalytic degradation of rhodamine B and methylene blue

Abstract

Titanium dioxide (TiO2) as photocatalyst is widely used in water purification, because many organic compounds can be decomposed and mineralized by oxidation and reduction processes taking place on the surface of TiO2. In this study, the composite of TiO2 nanoparticles (NPs) @ mesoporous silica nanoparticles (MSNPs) (TiO2@SiO2) were prepared by the sol–gel method. The prepared TiO2@SiO2 nanocomposite was modified by decorating silver nanoparticles (Ag NPs) (TiO2@SiO2–Ag) using a hydrothermal method. The TiO2@SiO2–Ag nanocomposite was characterized by field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and UV–Visible spectroscopy. The FE-SEM analysis revealed that the Ag NPs are uniformly spread on the TiO2@SiO2 nanocomposite which could highly enhance its photocatalytic activity. XRD analysis also confirmed the presence of Ag nanoparticles on the surface of TiO2@SiO2 nanocomposite. The TiO2@SiO2–Ag nanocomposite exhibited better photocatalytic performance in terms of degrading rhodamine B and methylene blue with the photo catalytic degradation efficiency of 92 and 85 % respectively under direct sunlight illumination. These results disclosed that the TiO2@SiO2–Ag nanocomposite can be exploited as a potential photocatalyst towards the degradation of dye studies.