Photocatalytic degradation of dibenzothiophene using La/PEG-modified TiO2 under visible light irradiation

摘要

While the photocatalytic degradation of various organic compounds under UV light irradiation has been widely investigated, visible-light-induced photocatalytic degradation of low levels of pollutants such as dibenzothiophene (DBT) is occasionally reported. In the present work, lanthanide/polyethylene glycol-modified TiO2 (La/PEG/TiO2) has been successfully synthesized by a sol-gel method. The photocatalyst was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-Vis diffusive reflectance spectroscopy, and energy dispersive X-ray analysis. Moreover, the photocatalytic degradation of DBT under visible light irradiation is investigated for the first time using the newly synthesized photocatalyst. The effects of important operational parameters such as initial DBT concentration, catalyst loading, pH, and amount of H2O2 on the degradation efficiency were studied. Kinetics parameters of the photocatalytic oxidation of DBT were also calculated. The results show that DBT decomposition occurs according to the Langmuir-Hinshelwood mechanism. The degradation products were analyzed by the GC-MS technique.