TiO_2-SiO_2复合气凝胶涂层的制备和光催化性能

利用TiCl4和工业水玻璃为原料,通过溶胶凝胶法制备TiO2-SiO2复合凝胶,用三甲基氯硅烷(TMCS)/乙醇(EtOH)/正己烷(Hexane)混合溶液对湿凝胶进行改性,常压干燥制备了TiO2-SiO2气凝胶,经150℃干燥所得的气凝胶具有多孔结构,获得的气凝胶比表面积达到646～816m2/g,孔体积达到1.52～2.19cm3/g。用乙醇作为分散剂,将气凝胶块体研磨成具有一定黏度的浆料,采用丝网印刷法制成TiO2-SiO2复合气凝胶涂层。利用X射线衍射(XRD)、扫描电镜(SEM)和孔径及比表面积分析仪(BET)对复合气凝胶的结构、形貌和孔性质进行了研究,通过分光光度计法分析了TiO2-SiO2复合气凝胶涂层光催化降解罗丹明B的性能,在可见光下照射4h后降解率达到77%。

Preparation of TiO2-SiO2 composite aerogel and its photocatalytic activity

TiO2-SiO2 composite gels were obtained with titanium tetrachloride and industrial waterglass as raw materials by sol-gel method and modified via ambient pressure drying using Trimethylchlorosilane/Ethanol/Hexane solution to obtain TiO2-SiO2 composite aerogels.The TiO2-SiO2 composite aerogels have porous structure with surface area reaching 648 to 816 m2/g and pore volume reaching 1.52 to 2.19 cm3/g after dried at 150 ℃.The TiO2-SiO2 composite aerogels were ground with ethanol as dispersant to obtain a kind of paint with proper viscosity.Then TiO2-SiO2 composite aerogel coating was prepared by screen printing method.The structure,morphology and pore characteristic of the aerogels were studied by XRD,SEM and BET analysis.The adsorption and photocatalystic degradation to RHB of the TiO2-SiO2 composite aerogel coating were investigated by the spectrophotometer method.