TiO_2超细粉制备及对典型有机试剂的光催化降解作用

PREPARATION OF ULTRAFINE TITANIUM DIOXIDE POWDER AND ITS DECOLORIZATION OF TYPICAL ORGANIC REAGENT

针对TiO2光催化降解典型有机试剂——甲基橙的问题,提出了以经乙酰丙酮化学修饰的钛酸四丁酯为前驱体溶胶-凝胶法水解制备超细粉TiO2的技术方案,用X射线衍射法对成品TiO2进行分析.制备得粒径为25nm的TiO2超细粉,经焙烧热处理,当TiO2超细粉中锐钛矿型为金红石型含量2～4倍时光催化活性较高.焙烧温度的升高和焙烧时间的延长,均使锐钛矿型的相对含量减少,金红石型的相对含量增加,TiO2粒径增大.少量的乙酰丙酮即可很好地控制钛酸四丁酯的水解速率.

Contraposed to the decolorization of typical organic reagentmethyl orange, ultrafine titanium dioxide powders were prepared by solgel method from the tetrabutyl titanate modified by acetylacetone as precursors. Some powers were analyzed by Xray diffraction(XRD). The crystallite size of the TiO2 powers with much more photocatalytic activity was 25 nm and the ratio of anatase and rutile after calcinating was from about 2 to 4. The comparative contents of anatase in the power decreased while the comparative contents of rutile and the crystallite size increased if calcinating temperature and time were increased. The velocity of hydrolysis of tetrabutyl titanate was able to be controlled easily with a few acetylacetone.