SiO2柱层状钛酸的制备及光催化性能

采用分步反应法制备SiO2柱层状钛酸(SiO₂-H₂Ti₄O₉)光催化材料, 研究了制备过程中烷基胺的链长、胺预撑后的洗涤方式以及与正硅酸乙酯(TEOS)水热反应时间等因素对SiO₂-H₂Ti₄O₉结构的影响. 以亚甲基蓝(Methylene Bule, MB)为探针反应物, 考察了SiO₂柱层状钛酸的光催化性能. 结果表明, 随着烷基胺链长增加, 层间距增大, 有利于在层间引入TEOS; 用1:1的乙醇水溶液洗涤正十二胺撑后的产物的结晶度显著高于用无水乙醇洗涤的产物; 胺撑后的产物与TEOS在130℃条件下水热反应两次可得到层间距为1.45nm、比表面积为148.4m²/g、结构较规整的SiO₂-H₂Ti₄O₉柱层状材料. 该柱层状材料对亚甲基蓝具有较高的光催化活性.

Preparation and Photocatalytic Performance of SiO2-Pillared Layered Titanate

SiO₂ pillared layered titanate (SiO₂-H₂Ti₄O ₉₎ was prepared from the layered K₂Ti₄O₉ via a step-reaction method. The influences of alkyl chain length of intercalated alkylamines, washing methods and the hydrothermal time of alkylamine reacted with TEOS on the structure of SiO₂-H₂Ti₄O₉ were investigated. The photocatalytic activities of SiO₂-H₂Ti₄O₉ were evaluated by photocatalytic oxidation of methylene blue(MB) aqueous solution. The results reveal that the interlayer spacing of alkylamine pre-intercalation samples increases with the increase of the chain length of alkylamines, and the crystallinity of the samples washed with ethanol solution(1:1, v/v) is enhanced compared with anhydrous ethanol. SiO₂-H₂Ti₄O₉ treated twice by TEOS at 130℃ has an interlayer spacing of 1.45nm and a specific surface area of 148.4m²/g. SiO₂ pillared layered titanate shows a higher efficiency of MB photo-degradation compared with its precursors K₂Ti₄O₉.