锐钛矿、金红石和板钛矿降解罗丹明B光催化活性的比较

摘要

详细考察并比较了采用低温制备的锐钛矿、金红石和板钛矿氧化钛降解罗丹明B的光催化活性.与传统高温焙烧制备的金红石相比,低温制备的金红石粒径小,比表面积大,表面羟基数目多,因此光催化效率明显增加.更重要的是,当锐钛矿和金红石具有相似粒径和比表面积时,金红石具有较高的光降解罗丹明B活性.对于板钛矿氧化钛而言,虽然其表观光催化活性(单位时间内降解的罗丹明B)远低于锐钛矿或金红石的表观光催化活性,但是其本征光催化活性(单位比表面积、单位时间内降解的罗丹明B)却远远高于锐钛矿或金红石的本征光催化活性.%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 futile 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 convetted RhB per hour than the anatase and mtile phases. However, its areal photocatalytic activity expressed in moles converted RhB per hour per surface area was much higher than that ofanatase and rutile TiO2.