Nanocrystalline TiO2 photocatalytic membranes with a hierarchical mesoporous multilayer structure:: Synthesis, characterization, and multifunction
Nanocrystalline TiO2 photocatalytic membranes with a hierarchical mesoporous multilayer structure:: Synthesis, characterization, and multifunction
复制标题
DOI：
10.1002/adfm.200500658
复制
发表时间：
2006-05-19
影响因子：
19
通讯作者：
Dionysiou, Dionysios D.
中科院分区：
文献类型：
--
作者：
Choi, Hyeok;Sofranko, Anna C.;Dionysiou, Dionysios D.
研究了一种新型的溶胶-凝胶浸渍法制备纳米TiO2光催化膜的方法，该膜具有较强的层次化介孔多层膜，性能得到改善。合成了不同摩尔比(吐温80/异丙醇/冰醋酸/四丙醇钛=R：45：6：1)的二氧化钛溶胶，其中以聚氧乙二醇单油酸酯(Tween80)为导孔剂，在不同的摩尔比(Tween80/异丙醇/冰醋酸/四丙醇钛=R：45：6：1)下，制备了不同孔结构的二氧化钛溶胶。将溶胶浸渍在自制的多孔氧化铝基板上，制成TiO2/Al_2O_3复合膜，烘干、焙烧，然后依次对不同的溶胶重复此过程。所得到的厚度为0.90微米的非对称介孔二氧化钛薄膜的孔径从2-6到3-8，从上到下呈现出分级变化的5-11 nm。此外，相应的孔隙率从46.2增加到56.7，增加到69.3%。与使用单一溶胶的重复涂覆工艺相比，分层多层工艺在不牺牲TiO2膜的有机保留和光催化活性的情况下显著提高了水的渗透性。所制备的TiO2光催化膜具有多功能，在有机污染物的分解、病原微生物的灭活、污染物的物理分离和自污染作用等高效水处理和回用系统中具有巨大的潜力。
A novel sol-gel dip-coating process to fabricate nanocrystalline TiO2 photocatalytic membranes with a robust hierarchical mesoporous multilayer and improved performance has been studied. Various titania sols containing poly(oxyethylenesorbitan monooleate) (Tween 80) surfactant as a pore-directing agent to tailor-design the porous structure of TiO2 materials at different molar ratios of' Tween 80/isopropyl alcohol/acetic acid/titanium tetraisopropoxide = R:45:6:1 have been synthesized. The sols are dip-coated on top of a homemade porous alumina substrate to fabricate TiO2/Al2O3 composite membranes, dried, and calcined, and this procedure is repeated with varying sols in succession. The resulting asymmetric mesoporous TiO2 membrane with a thickness of .0.9 mu m exhibits a hierarchical change in pore diameter from 2-6, through 3-8, to 5-11 nm from the top to the bottom layer. Moreover, the corresponding porosity is incremented from 46.2, through 56.7, to 69.3 %. Compared to a repeated-coating process using a single sol, the hierarchical multilayer process improves water permeability significantly without sacrificing the organic retention and photocatalytic activity of the TiO2 membranes. The prepared TiO2 photocatalytic membrane has great potential in developing highly efficient water treatment and reuse systems, for example, decomposition of organic pollutants, inactivation of pathogenic microorganisms, physical separation of contaminants, and self-antifouling action because of its multifunctional capability.