Preparation and Photocatalytic Properties of Mo-Doped TiO_2@Fly Ash Cenospheres for Degradation of Methylene Blue

摘要

Mo-doped titanium dioxide (TiO_2)-coated fly ash cenosphere (FAC) was synthesized by the sol-gel method. The novel photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), and X-ray photoelectron spectra (XPS). The results showed that the catalyst maintains the structure of anatase (TiO_2), and the majority of doped Mo ions existed as Mo~(6+) substitution in anatase lattice, which caused redshift of TiO_2 light absorption wavelength, broadening the light absorption range and making more effective use of solar energy. The photocatalytic activity of Mo-TiO_2@FAC sample for the degradation of methylene blue (MB) under visible light irradiation was investigated. The photocatalyst that was calcined at 550 °C with Mo/Ti molar ratio of 0.3% and concentration of 2 g/L exhibited the optimal photodecomposition property.