Investigation on F-B-S tri-doped nano-TiO_2 films for the photocatalytic degradation of organic dyes

摘要

F-B-S tri-doped titanium dioxide thin films on common glass were prepared by a modified sol-gel method, in which tetrabutyl titanate (Ti(OC _4H_9)_4) was chosen as the precursor and boric acid (H_3BO_3), sodium fluoride (NaF), and thiourea (N _2H_4CS) were employed as boron, fluorine, and sulfur sources, respectively. The microstructure and optical property were characterized by X-ray diffraction, high-resolution field emission scanning electron microscopy, N_2 adsorption-desorption isotherms, photoluminescence spectrum, and UV-Vis diffraction reflectance spectroscopy. The photocatalytic performances were evaluated by decomposition of organic dyes in solution. The experimental results revealed that the F-B-S tri-doped TiO _2 thin film was composed of uniform round-like nano-particles with the size range of 5-8 nm. F-B-S tri-doping not only significantly promoted the UV-induced photodecomposition activities of TiO_2 films but also extended the optical response of TiO_2 red shift to visible light region, herein improving the visible light-induced degradation of organic dyes. The improvement mechanism by F-B-S tri-doping was also discussed.