聚乙二醇包覆的TiO_2粉体的光催化活性

Photocatalytic Activity of TiO_2 Powder Coated by Polyethylene Glycol

采用TiCl_4水解法制备了被聚乙二醇(PEG)包覆的TiO_2粉体,并通过X射线衍射(XRD)、透射电镜(TEM)对粉体的物相组成及表面形貌进行表征。将合成的TiO_2粉体用于2,4-二氯苯氧乙酸(2,4-DPA)的降解反应中,利用荧光光度计以及紫外可见分光光度计等技术手段,考察溶液的荧光及紫外吸收强度随光照时间的变化关系,并以此判断包覆的TiO_2的光催化性能。结果表明:PEG包覆的TiO_2能降低2,4-DPA溶液的荧光强度和紫外吸收强度,有明显的光催化降解作用,且以相对分子质量较大的PEG包覆的效果较好。

TiO2 powder coated by polyethylene glycol （PEG）, a photocatalyst, was prepared by hydrolyzing method of TiCl4 and its composition and appearance were characterized by XRD and TEM. The PEG - coated TiO2 powder as photodegradation catalyst was used in degradation of 2, 4 -dichlorophenoxyacetic acid（2,4 - DPA）. The changes of fluorescence and UV absorption intensities of the 2,4 -DPA solution with UV exposure time were investigated using fluorescent spectrometer and UV -vis spectrophotometer to determine the photocatalytic activity of the coated TiO2. The experimental results showed that the PEG - coated TiO2 powder could obviously reduce the intensities of fluorescence and UV absorption of 2,4- DPA and had good photocatalytic degradation. The larger the molecular weight of PEG was, the better the photocatalytic degradation of the PEG - coated TiO2 powder were.