复合模板剂及超临界干燥法制备介孔TiO2研究

Preparation of Mesoporous Titanium Dioxide Using a Composite Surfactant Template and Super-Critical Desiccation Technique

以吐温-80（Tween-80）和司班-80（Span-80）为复合模板剂,钛酸四正丁酯（TBOB）为钛源,应用溶胶-凝胶（sol-gel）法及超临界干燥法合成介孔TiO2材料。采用扫描电镜（SEM）、透射电镜（TEM）、X衍射（XRD）等测试方法对样品的显微结构及晶相进行分析及表征。结果表明凝胶的干燥工艺、煅烧温度及不同Tween/Span比对介孔结构有较大影响。采用常温干燥方法难得到介孔结构,而超临界干燥可直接得到介孔TiO2。提高煅烧温度可以提高TiO2的结晶度。Tween/Span比对孔径的影响较大,当Tween/Span=2∶1时,能得到孔径在10～20nm的介孔TiO2。

Mesoporous TiO2 was synthesized through super-critical desiccation technique and sol-gel method using Tween-80 and Span-80 as a composite surfactant template, ethanol as solvent, nitric acid as inhibitor and Tetrabutyl titanate （Ti（ OC4H9）4, TBOT） as a titanium source. The micro-morphology and crystalline structure of the mesoporous TiO2 were characterized by TEM, SEM and XRD. Results indicate that： the process of desiccation, heat-treating temperatures and the ratio of Tween/Span showed a great influence on the mesoporous structure. It is hard to obtain the mesoporous structure using the normal dry method, while using super-critical desiccation technique, the anatase mesoporous TiO2 could be synthesized directly. It was found that the ratio of Tween/Span showed a great influence on the aperture, when the ratio of Tween/Span was 2： 1, the aperture of synthesized mesoporous TiO2 was about 10 - 20nm.