Synthesis and Characterization of Visible-Light-Active TiO2-Based Photocatalysts

TiO₂ has gained great popularity for environmental treatment and purification purposes; however, it shows poor absorption of visible light and requires ultraviolet (UV) light for activation. Here we have successfully synthesized a visible-light-active carbon and nitrogen co-doped TiO₂ catalyst. The catalyst was characterized by Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS). Results showed that the optical response of modified TiO₂ was extended to the visible light region. Nitrogen substituted for some of the lattice oxygen atoms and most of the carbon was in the form of elemental carbon. The photocatalytic tests indicated that the modified catalyst demonstrated higher visible-light activity for the degradation of methylene blue (MB) than TiO₂.