Preparation of TiO2/Ag[BMIM]Cl Composites and Their Visible Light Photocatalytic Properties for the Degradation of Rhodamine B

In order to degrade toxic pollutants such as dyes during the process of sewage treatment, considerable attention has been paid to photocatalytic technologies. In this paper, TiO2/Ag[BMIM]Cl (1-butyl-3-methyl imidazolium chloride ([BMIM]Cl)) nanocomposites were prepared with TiO2 as the carrier, silver ions as dopants and ionic liquids (IL) as modifiers. The morphologies, microstructures, crystalline structure and optical properties of the TiO2/Ag[BMIM]Cl nanospheres are investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), total organic carbon (TOC), and UV-vis diffuse reflectance spectrum (UV-vis DRS) techniques. The TiO2/Ag[BMIM]Cl nanocomposites can selectively degrade rhodamine B (Rh B) under visible light because of the unstable quaternary ammonium salt. The as-obtained nanocomposites exhibit better photocatalytic activity performance than pure TiO2, TiO2/IL, and TiO2/Ag+. The experimental results show that the Rh B degradation rate can reach 98.87% under optimized producing conditions by using the TiO2/Ag[BMIM]Cl composites as the catalyzer. It shows that simultaneous doping with silver ions and ionic liquids can significantly improve the photocatalytic activity of TiO2 in Rh B degradation, indicating the formation of photosensitive AgCl in the process of TiO2/Ag[BMIM]Cl preparation. Ag+ and IL addition exchange the band gap of TiO2 and lengthen the visible wavelength range of the composite. The material has the advantages of low cost, facile preparation and reusability with the excellent degradation effect of Rh B.