低温制备锐钛矿型TiO_2溶胶的性能研究

Study on properties of anatase TiO_2 sols prepared in low temperature

采用溶胶-凝胶法,以水为溶剂,在低于70℃下直接合成纳米锐钛矿型TiO2溶胶,研究了反应温度、pH值对溶胶晶型、晶粒大小和稳定性的影响。以不同光照下对亚甲基蓝的降解,评价了溶胶的光催化活性。结果表明:较低pH值下溶胶中的TiO2出现了金红石相与锐钛矿相组成的混晶相,而pH值相对较高时则得到纯锐钛矿相TiO2;在紫外光、日光灯和太阳光下,与P25对亚甲基蓝的降解相比,同等条件下所制备的TiO2溶胶显示出更好的光催化活性;混晶相TiO2溶胶的光催化性优于纯锐钛矿相TiO2溶胶。

Nano anatase TiO2 sols were directly prepared below 70℃ by sol-gel method. The influences of temperature and pH value on crystalline structures, particle size, and stability of sols were investigated. The photocatalytic activities of sols were characterized by degradation of methylene blue under UV light, fluorescent light and sunlight. The results show that the mix-crystalline TiO2 appeared in lower pH value and anatase TiO2 appeared in higher pH value. The sols demonstrate more excellent photocatalytic activity than P25 and the mixcrystalline TiO2 sol has higher photocatalytic activity than that of anatase TiO2.