Effect of filler types and calcination temperature on the microstructure and the nitric oxide photocatalytic activity of composite titanium dioxide films

The composite titanium dioxide (TiO2) films coating on the woven glass fabric were prepared by a modified sol-gel process, using pre-calcinated TiO2 nanoparticle or silica gel as filler. The characterized physicochemical properties of the prepared catalyst films showed that the specific surface area, the microstructure and the crystal structure of the catalysts were greatly affected by the fillers and the calcination temperature. The physicochemical properties of composite films and the photocatalytic activity of nitric oxide (NO) show that the pre-calcinated TiO2 nanoparticle is more favorable than silica gel as filler. The pre-calcinated TiO2 nanoparticle filler can increase the photocatalytic activities of the catalysts by increasing the specific surface area, introducing a bimodal mesoporous structure, and creating a polymorphous crystal structure. And the TiO2-TiO2 film calcinated at 400 °C exhibits the highest photocatalytic activity for NO oxidation and is more active than Degussa P25.