Synthesis and photocatalytic properties of porous TiO_2 films prepared by ODA/sol-gel method

摘要

Porous TiO_2 films were deposited on SiO_2 pre-coated glass-slides by sol-gel method using octadecylamine (ODA) as template. The amount of ODA in the sol played an important role on the physicochemical properties and photocatalytic performance of the TiO_2 films. The films prepared at different conditions were all composed of anatase titanium dioxide crystals, and TiO_2 crystalline size got larger with increasing ODA amount. The maximum specific surface area of 41.5 m~2/g was obtained for TiO_2 powders prepared from titanium sol containing 2.0 g ODA. Methyl orange degradation rate was enhanced along with increasing ODA amount and reached the maximal value at 2.0 g addition of ODA. After 40 min of UV-light irradiation, methyl orange degradation rate reached 30.5% on the porous film, which was about 10% higher than that on the smooth film. Porous TiO_2 film showed almost constant activity with slight decrease from 30.5% to 28.5% after 4 times of recycles.