Characterization and photocatalytical analysis of N, Cd-codoped TiO2 synthesized by modified sol-gel method

N, Cd-codoped TiO₂ have been synthesized by sol-gel method coupling with thermolysis. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), UV-visible diffuse reflectance spectra (DRS), and X-ray photoelectron spectroscopy (XPS) respectively. The photocatalytic activities of samples were studied on the degradation of methyl orange (MO). XRD results showed that photacatalysts possessed an anatase crystalline framework having particle sizes of 10-15 nm. XPS analysis indicated that N atoms were incorporated into the TiO₂ crystallattice, while Cd atoms existed on the crystal surface. Doping resulted in the observation of optical absorption edges shifting to the red light. The optical absorption edge of N-doped TiO₂ and N, Cd-codoped TiO₂ was 425 nm and 435 nm, respectively, which illustrated that the products represented photoactivity in the visible region. The products represented good performance in degradation on MO, and the degradation rate corresponding to the N, Cd-codoped TiO₂ catalyst was the highest. It indicated a strong N-Cd synergistic interaction appeared to play a decisive role in driving the excellent photoactivity performance of N,Cd-codoped TiO₂.