Photosensitizing Nano-Crystalline Titania by Doping Nitrogen

Nitrogen-doped nano-crystalline titania was prepared by the reaction of titanic chloride and ammonia gas or ammonia water using methonal or isopropanol as solvent. Excellent visible light (absorption) was detected by the UV-Vis spectrophotometer. The absorption threshold value was transferred to 830 nm. Because the nitrogen element was introduced in the precursor of TiO_2, the stronger visible light absorption was obtained at a low calcining temperature 350 ℃ comparing to the ammonia gas treating method at 600 ℃ reported in the literature. The state of nitrogen existing in the precursor and in the TiO_2 lattice exerted important influence on the result of visible light sensitization.