Of Tio <sub> 2 </ Sub> Nanotubes Prepared By Template Method And Photocatalytic Applied Research

This dissertation studied on the preparation of nano-sized TiO2 and its photocatalytic properties. The syntheses of transparent colloidal solutions of TiO2 were presented, which were analyzed by TEM and UV-vis absorption spectroscopy. Ti02 nanotubes were fabricated by the template of porous anodic alumina. Various measurements including SEM, TEM, XRD, DRS and fluorescence spectroscopy were used to characterize the diameter, morphology, structure, composition and absorption edge of TiO2 nanotubes. Photocatalysis of TiO2 nanotubes in the anatase form was studied for the photocatalytic degradation of sodium dodecyl benzene sulfonate (SDBS).Three kinds of T1O2 sols were prepared by hydrolysis of TiCU and Ti(OC4H9)4. TEM showed that TiO2 particles with diameter 20 nm were distributed homogeneously in the sols. Their absorption edges in the UV-vis spectra exhibited blue shift with decreasing particle size.TiOs nanotubes, characterized by rough walls, the outside diameter of 150 nm and the longest length of 70 urn, were found in the pores of an alumina template membrane. They were found to be polycrsytal in anatase after heat treatment at 400 癈. The morphology and optical properties between TiO2 films and nanotubes were compared. SEM showed that walls of Ti02 nanotubes were composed of many small round crystals but there were no any fine structures on Ti02 film. DRS showed that there were obvious absorption edges around 400 nm for the two specimens and TiO2 nanotubes had an absorption edge blue shifted compared with the TiO2 film. Fluorescence spectra showed that both of them had a intense luminescence band in the range of 300-500 nm and a weak band in 600-800 nm, but the luminescence in 300-400 nm on the TiO2 nanotubes was more intense and blue shifted compared with that on the TiO2 film.Five test conditions for degradation of 1.900x10-4 mol/L SDBS by use of TiO2film or nanotubes as photocatalysts were investigated. TiO2 nanotubes showed excellent activities in photocatalysis in the case, revealing a potential application in environmental control. Results were discussed on the morphology, DRS and fluorescence spectra of the TiO2film and nanotubes.