EFFECT OF N, B, F AND C CO-DOPING ON THE PHOTO DEGRADATION OF TITANIUM DIOXIDE PREPARED BY SOL-GEL PROCESS

摘要

Titanium dioxide has been a great interest because of its photocatalytic activity and pollutant degradation. Photocatalytic activity of titanium dioxide doped by carbon, nitrogen, boron and fluorine under light irradiation is much better than photocatalytic activity of undoped TiO_2. Because the dopants such as nitrogen, boron, fluorine and carbon were found that they shift the optical absorption threshold of TiO_2 into longer wavelength region. In this study, TiO_2 was prepared by sol-gel technique for increasing specific surface area, using TiCl_4 as the titanium oxide precursor and ammonia solution as the basic catalyst. A new photocatalyst based on carbon, nitrogen, boron and fluorine doped prepared TiO_2 was successfully prepared using stir and microwave from a single precursor, tetraethylammonium tetrafluoroborate (TEATFB). The catalysts were characterized by SEM and XPS analysis. The capacity of photocatalyst was evaluated for the photodegradation of procion blue dye. By the benefit of large specific surface area of TiO_2 prepared by sol-gel process, catalysts showed initial fast removal of dye. The photoactivity shows that the doped catalysts significantly promote the light reactivity than undoped TiO_2. The commendable photoactivity of prepared catalysts is predominantly attributable to the doping of anions which may reduce the band gap.