TiO_2毛细管整体柱的制备及其光催化性能的研究

Preparation of TiO_2 thin films deposited on a capillary and their photocatalytic activity

以钛酸四丁酯为钛源,乙醇和水分别为溶剂和反应物,醋酸为催化剂控制反应速度,聚乙二醇作为分散剂,通过溶胶-凝胶法制备出二氧化钛毛细管整体柱,在毛细管内壁上通过化学键的作用键合了一层二氧化钛薄膜,用于光催化降解水中的有机污染物。通过改变钛源的量控制二氧化钛薄膜的厚度,加入不同分子量的聚乙二醇提高薄膜的比表面积,并探究了煅烧温度对二氧化钛晶型的影响。将15 mg/L的有机大分子罗丹明B水溶液注入制备好的毛细管整体柱内,在紫外光照射下进行光催化降解实验,30 min内降解率为98.5%。循环使用多次后,薄膜脱落较少,具有良好的催化效果,避免了对环境的二次污染。

A titania capillary column has been prepared by a sol-gel method. In the process of sol preparation,tetrabutoxytitanium was used as a source,ethanol as solvent and deionized water as reactant,with acetic acid as the stabilizer to control the reaction speed,and polyethylene glycol as dispersant. Through the chemical reaction of the sol in the capillary,the titania film was immobilized on the inner wall of the capillary for photocatalytic application.The thickness of the films was controlled by varying the tetrabutoxytitanium concentration. The specific surface area of the films could be increased by adding polyethylene glycol with different molecular weight. The effect of calcination temperature on the crystal form of titania was also investigated. For a Rhodamine B solution of 15 mg/L,the photodegradation efficiency was 98. 5% in 30 min under UV irradiation. The catalysts could be recycled with almost the same efficiency for several cycles,indicating the firm immobilization of the films on the inner wall of the capillary. Thus,this method can avoid secondary pollution of the environment.