Photocatalytic Degradation of Rhodamine B on Anatase, Rutile, and Brookite TiO2

This study compared the photocatalytic activities for the degradation of Rhodamine B (RhB) in aqueous solutions of anatase, rutile, and brookite TiO2. The TiO2 powders were prepared at low temperature. As compared with rutile obtained by a conventional high temperature calcination, the rutile TiO2 prepared by the low temperature route had a smaller particle size, higher surface area, and more surface hydroxyl groups, and it gave a high photocatalytic activity. Rutile gave a faster photocatalysis reaction rate than anatase TiO2 for the same particle size and surface area. A pure brookite phase showed a lower photocatalytic activity when this was expressed in moles converted RhB per hour than the anatase and rutile phases. However, its areal photocatalytic activity expressed in moles converted RhB per hour per surface area was much higher than that of anatase and rutile TiO2.