一维掺杂TiO2纳米管/分子筛复合材料的制备及选择性光催化性质研究

Due to good electrical transport, high surface area and low charge carriers combination losses, one-deminational self-ordered TiO2 nanotubes demonstrate various excellent properties.This kind of material is explored in many applications such as photocatalysis and water spillting. In this project, after fabrications of Nb doped TiO2 nanotubes by electrochemical anodization, zeolites will be synthesized within the nanotubual layer by hydrothermal method. We will focus on producing a novel TiO2/zeolite nanocomposite to enhance both photocatalytic activity and selectivity. Here,zeolite systems act as adsorbents of some orgaincs to enrich a desired specises in nanotubes depending on the specific pore size. Doped Nb is to be great help in photo-electron transport in TiO2 nanotube and modification of the bulk electronic structure, then to produce a higher photocatalytic activity. In order to make clear the effcets of selective photocatalysis on nanocomposite, we will explore the chemical composition, pore size, channel structure and surface hydrophobic/hydrophilic properties of zeolites. Also,the optimal ratio of anatase and rutile in Nb-doped TiO2 nanotube for a higher photocalytic activity will be investigated. The aim of this project is to synthesize the promising photocatalytic functionality of the Nb-doped TiO2 nanotube with the selective capturing ability of zeolites for producing a new type of photocatalyst.

一维自组装有序的TiO2纳米管由于具有高比表面积和快速电子传输等特点在光催化降解有机污染物和光解水制氢等领域受到国内外的广泛关注。本项目提出一种新的研究思路，以同时提高光催化降解效率和增加光催化选择性两方面为目标，将Nb掺杂的TiO2纳米管和分子筛结合。首先用电化学阳极氧化法使用Ti-Nb合金制备Nb掺杂的TiO2纳米管，然后将硅铝酸盐类分子筛以水热法直接生长在管中。利用Nb的掺杂效应提高光生电子在TiO2中的传输性能及改变TiO2的能带结构以提高光催化活性；利用不同分子筛特有的孔道尺寸效应对目标分子进行选择性吸附。研究不同种类分子筛的化学组成、孔径大小、孔道结构及表面亲疏水性对光催化的选择性的影响，同时探究Nb掺杂TiO2纳米管中锐钛矿和金红石的最佳比例，制备出具有高选择性高活性的新型光催化剂。