PREPARATION OF NANOSIZED TiO_2 BY SOL-GEL METHOD AND POSTSYNTHESIS HYDROTHERMAL TREATMENT

摘要

The nanosized TiO_2 is a very promising compound applied for: the preparation of ceramic for high technologies, support in the heterogeneous catalysis, photocatalysis, as a sensor for gas indication, membrance etc. Nanocrystalline TiO_2 has been obtained by sol-gel method. Two kind of stabilized titania sol are prepared. The process of hydrolysis is regulated by addition of acetylacetone to one of the solutions. The final nanocrys-talline powder is obtained by two types of treatments: ⅰ) heating in the range 80-700℃, ⅱ) postsynthesis hydrothermal treatment of dried powder. The size of the crystallite of obtained powders is in the region 8.7-31.3 nm and specific surface area varies from 11-210m~2/g. A special attention is drawn to the formation of anatase crystalline modification which is a very perspective as photocata-lyst. The characterization of the obtained samples is carried out by the methods of: thermal analysis, XRD (including structural analysis), UV, VIS spectral analysis, and modified BET method.