TiO_2纳米晶介孔粉体的制备及其结构和光催化性能研究

Study on Preparation of Meroporous Nanocrystalline TiO_2 Powders and Their Structures and Photocatalytic Activities

系统考察了胶溶法制备水合TiO_2溶胶过程中胶溶剂加入量、解胶温度和粒子浓度等工艺参数对解胶时间和溶胶Z均粒径的影响,获得了粒径小且分布窄的水合TiO_2溶胶的最佳制备工艺条件;溶胶经50℃陈化并干燥后所得的干凝胶为结晶度较低的锐钛矿相;干凝胶经550℃和650℃煅烧后制得了孔径集中分布在40 nm左右的TiO_2纳米晶介孔材料,经750℃煅烧后介孔消失;650℃煅烧所得的约含14%金红石相的混晶型TiO_2粉末的光催化活性优于550℃煅烧所得的产物。

The effects of the peptizer amount, the peptizing temperature, and the particles concentration, on the peptizing time and the Z average size of the TiO2 sols prepared by the peptization method were systematically investigated. The optimum conditions for preparing the sol with small size and narrow size distribution were obtained. The xerogel obtained by aging and drying the sol at 50 ℃ was anatase with low crystallinity. The mesoporous nanocrystalline TiO2 materials whose pore distribution was centered around about 40 nm, were obtained by calcining the xerogel powders at 550 ℃ and 650 ℃, and the mesopores disappeared when calcined at 750 ℃. The photocatalytic activity of the powder obtained at 650 ℃, which had 14 % of rutile, was superior over that of the powder obtained at 550 ℃.