Preparation and characterization of the Sb-doped TiO2 photocatalysts

Doped TiO2 photocatalysts have been prepared by a coprecipitation method. U niformly doped nanocrystalline TiO2 of 10-20 nm sizes was synthesized by ca lcinating the coprecipitated gels at 400-650 degreesC. Photocatalytic chara cterization along with the microstructural investigation for each catalyst provides better understanding of the photocatalytic behavior. It was found that the photodegradation of methylene blue (MB) was a complex function of the doping type and its concentration and the microstructural characteristi cs of the catalysts. Antimony doing significantly improved photocatalytic p erformance as compared to the undoped TiO2. Post-treatment of the as-precip itated wet doped Ti gels in an organic solvent also increased the surface a rea, forming approximately 8 nm size doped TiO2 with surface area similar t o 149 m(2)/g. Superior catalytic activity was observed in the Sb-doped TiO2 samples at a doping concentration ranging from 1 to 5 at%. Using the 5 at% Sb-doped TiO2 catalyst treated in butanol, 100 ppm of MB could be decompos ed completely within 1 h, which was better than the commercial Degussa P-25 . (C) 2001 Kluwer Academic Publishers.