宽光谱激发响应的锐钛矿纳米晶TiO_2溶胶

RESEARCH ON NANOMETER CRYSTAL ANATASE TiO_2 SOL EXCITATED BY BROAD-RANGE LIGHT SPECTRUM

采用钛酸丁酯:水:无水乙醇:盐酸以摩尔比为1:175:7.5:0.07的体系,以溶胶-凝胶工艺制备出含有锐钛矿纳米晶体的二氧化钛溶胶。溶胶在常温下干燥后所得粉体,无需常见的高温热处理即为锐钛矿晶型;对溶胶做X射线吸收精细结构分析,发现液相中存在锐钛矿晶体结构;透射电镜结果显示溶胶中含有四方形锐钛矿晶体。在200～1000nm波段光线照射下,溶胶(并非粉体或者薄膜)可使罗丹明B褪色,即溶胶具有紫外、可见、近红外的宽光谱激发响应能力。文章认为,量子效应导致的中间态亚稳能级,可以让较少激发能的跃迁电子短暂停留,并使被催化物质分子内键合弱化或断裂,从而导致有机物被分解。

Anatase TiO2 sol containing nano crystals was prepared in sol-gel method, using Ti（OC4H9）4, H2O, CaH5OH and HCl in mol ratio 1：175：7.5：0.07. The powders after drying the sol at room temperature get anatase pattern in X-ray Diffraction analysis. X-ray absorpton fine structure analysis reveals that there are anatase structures in the sol. There are nanometer foursquare anatase crystals in the image of transmission electron microscope. Because of the nano crystals, the sol can photocatalyze Rhedamine B under the lights of 200-1000nm wavelengh range, without any traditional high-temperature heat treatment. The excitated electrons can temporarily stay at the metastable energy levels, which was created by the quantum effect of the nano crystals, and can weaken or break the bonds of organic molecules.