Preparation Of Nano Rutile Titania At Low Temperature And Their Photocatalytic Capability

Titania (TiO₂), which can decompose most organic pollutants into into CO₂ and H₂O under UV irradiation in air and water, has become a hot research area because of its attractive application in the treatment of environmental pollutants. Rutile TiO₂ is commonly thought to have higher preparation temperature and very low catalytic activity, but it is a chemically more stable phase and has a extent exitation wavelengths with broad application. Thereby, to study how to obtain rutile TiO₂ at low temperature and improve its catalytic activity is very interesting.In this paper, Titanium trichloride (TiCl₃) solution was used to prepare rutile TiO₂ directly via hydrothermal treatment at low temperature. The influence of concentration of TiCl₃ solution, reaction temperature and aging time on TiO₂ crystalline phase, crystallinity, morphology and size of TiO₂ were discussed in detail. By adjusting reaction conditions, nanocrystalline rutile TiO₂ of regular rod-like particles with about 15×80 nm was achieved. It showed high photocatalytic activity similar to commercial nano anatase TiO₂ in degradation of methyl orange. These powders were characterized by XRD, TEM, TG, FT-IR and FL. It showed that higher photocatalytic activity of rutile TiO₂ probably attribute to smaller particle size, higher crystallinity and more active hydroxyl groups.Choosing H₂O₂, KClO₃, KBrO₃, KIO₃, KIO₄ and H₇PW₁₂O₄₂(HPW) as electron acceptors, the effect of them on photoactivity of rutile TiO₂ prepared at low temperature was studied and compared with supertiny anatase, P25 and rutile TiO₂ calcined at high temperature. The results indicated that the rutile TiO₂ prepared at low temperature has best sensitivity to electron acceptors and its photoactivity was enhanced surprisingly even better than P25 by addition of a small quantity of H₂O₂, KBrO₃, KIO₃ and KIO₄. Distinguishingly, HPW made ruitle TiO₂ losing its photoactivity while enhanced photoactivity of anatase and P25.