基于液晶模板的蒸发诱导自组装技术合成高催化活性的有序介孔氧化钛

摘要

Ordered mesoporous TiO2 (OMPT) was prepared by an evaporation induced self-assembly technique using liquid crystal as template. The key factors affecting the methylene blue (MB) oxidation efficiency were investigated, including the initial concentration of MB, pH value and catalyst concentration. The results show that the obtained OMPT has high thermal stability and shows a 2D hexagonal mesostructure with the small particle size and high surface area, which lead to higher degradation efficiency than commercial P25 or nanoparticle TiO2 (NPT) fabricated by sol-gel process. The optimal conditions are 5 mg/L MB, pH 6 and 1.5 g/L OMPT for the fastest rate of MB degradation. Total organic carbon (TOC) analysis indicates complete mineralization of MB in 240 min by OMPT, with rate constant higher than NPT or P25.%利用蒸发诱导自组装技术，用液晶为模板制备有序介孔氧化钛(OMPT)，探讨影响亚甲基蓝(MB)氧化降解效率的主要因素，包括MB的初始浓度、pH值和催化剂浓度。结果表明，所获得的OMPT具有二维六方介孔结构，粒径小，比表面积大，表现出高的热稳定性，这些都导致其比催化剂 P25和溶胶-凝胶法制备的纳米氧化钛颗粒(NPT)有更高的降解效率。在MB浓度5 mg/L、pH 6和OMPT浓度1.5 g/L的条件下，MB的降解率最快。总有机碳(TOC)分析表明，OMPT在240 min内实现了对MB的完全矿化，其速率常数高于P25和NPT的。