SnO2-TiO2复合光催化剂的制备和性能

采用均匀沉淀法在超细TiO2表面包覆SnO2,制备出SnO2-TiO2复合光催化剂,并用EDS,XRD,TEM和BET比表面积测定等手段进行了表征.以活性艳红X-3B溶液为模拟废水,考察了SnO2-TiO2的光催化活性.结果表明,复合粒子由锐钛矿型TiO2和金红石型SnO2组成;与纯TiO2相比,SnO2-TiO2的光催化活性有较大提高,SnO2最佳包覆量为18.4%.复合光催化剂活性的提高归因于不同能级半导体之间光生载流子的输运和分离.

PREPARATION AND PROPERTIES OF SnO2-TiO2 COMPOSITE PHOTOCATALYSTS

Hydrous SnO 2 coated ultrafine TiO 2 particles have been synthesized by using the homogeneous precipitation method. The products thus formed have been separated, dried, and calcined to form crystalline SnO 2 TiO 2 composite particles which have been characterized by EDS, XRD, TEM and BET surface area. The composite particles, pure ultrafine TiO 2, commercial TiO 2, and pure SnO 2 have been employed in photocatalytic degradation of azo dye active red X 3B in aerated solution. The results show that the photocatalytic activity of the composite particles is higher than that of pure ultrafine TiO 2 and commercial TiO 2 particles, and the optimum loading of SnO 2 on TiO 2 is 18 4%. The enhanced degradation rate of X 3B using SnO 2 TiO 2 composite photocatalysts is attributed to the increased charge separation in these systems.