摘 要

TiO₂以其高稳定性、低成本、无毒、无二次污染等优点在废水处理、大气净化、杀菌消毒等方面具有广泛的应用前景。Mn作为具有多变价的过渡金属之一，因其氧化物和氢氧化物表现出的化学吸附作用及可见光区的光响应波长，在改性TiO₂中是一种良好的掺杂剂。

本文以四氯化钛为钛源，氯化亚锰为添加剂，采用自组装的方法，以巯基（-SH）为功能团，活性炭纤维布为基底，低温液相反应体系中制备Mn/TiO₂纳米薄膜，以罗丹明B为目标降解物，探讨了不同的实验影响因素及添加方式（掺杂、复合）对TiO₂光催化降解效率的影响。并用TEM对最佳参数下的TiO₂光催化剂进行结构、粒径大小、形貌等的表征。发现Mn² 掺杂TiO₂纳米薄膜、Mn_xO_y-TiO₂纳米薄膜的光催化活性相比无掺杂的TiO₂纳米薄膜均有显著提高，但Mn_xO_y-TiO₂纳米薄膜的光催化活性几乎没有提高。本文主要从TiO₂晶型种类和Mn-O-Ti键的结合等方面探讨了制备方法对TiO₂光催化活性的影响机理。

关键词：自组装；锰掺杂；TiO₂；光催化

Abstract

TiO₂ is widely used in water treatment、air cleaning、sterilization and disinfection because of its high stability、low price、non-toxic、without secondary pollution.As one of the different valence transition metal,Mn is a great dopant in modifying TiO₂ owing to its oxide and hydroxide’s chemical absorption and wave of photoresponse in visible light.

Mn-doped nano-TiO₂ thin films were synthesized by molecular self-assembly method from aqueous system at low temperature by this paper with TiCl₄ as Ti resource，MnCl₂ as Mn resource，-SH as functional group，activated carbon fiber as basement and rhodamine B as target to discuss how different influence factors and adding methods(dopant and compound) influence photocatalytic effciency of TiO₂.And characterize TiO₂ photocatalyst in its optimal parameter under TEM with its structure、grain size、morphology.It can be found that compared to undoped nano-TiO₂ thin film，photocatalytic activity of Mn-doped nano-TiO₂ thin film and Mn_xO_y-TiO₂ nano-film both are markedly enhanced，but photocatalytic activity of Mn_xO_y-TiO₂ nano-film is hardly any enhanced.This paper discusses influence mechanism of photocatalytic activity of TiO₂ with different preparation methods，in terms of crystal kinds of TiO₂ and Mn-O-Ti bond et al.

Key Words: self-assembly；Mn-doped；TiO₂；photocatalysis

目录

第1章 绪论...................................................................................................................................1

1.1 光催化作用..........................................................................................................................1

1.1.1 TiO₂光催化原理............................................................................................................1

1.1.2 Mn² 改性TiO₂...............................................................................................................1

1.2 活性炭结构..........................................................................................................................1

1.3 分子自组装技术..................................................................................................................2

1.3.1 分子自组装概念...........................................................................................................2

1.3.2 分子自组装单层制备机理...........................................................................................2

1.4 研究背景、目的及意义、内容及目标..............................................................................3

1.4.1 研究背景.......................................................................................................................3

1.4.2 研究目的及意义...........................................................................................................3

1.4.3 研究内容及目标...........................................................................................................4

1. 纳米Mn/TiO₂薄膜的制备及表征...................................................................................5

2.1 实验部分..............................................................................................................................5

2.1.1 试剂和仪器...................................................................................................................5

2.1.2 Mn² 修饰TiO₂纳米薄膜最优条件的制备..................................................................5

2.1.3 Mn² 修饰TiO₂纳米薄膜正交实验..............................................................................7

2.1.4 Mn² 修饰TiO₂纳米薄膜表征....................................................................................10

2.1.4.1 Mn² 掺杂TiO₂纳米薄膜显微结构分析.............................................................10

2.1.4.2 Mn_xO_y-TiO₂纳米薄膜显微结构分析..................................................................12

2.1.4.3 TiO₂-Mn_xO_y纳米薄膜显微结构分析..................................................................15

2.2 本章小结...........................................................................................................................16

1. Mn² 修饰TiO₂纳米薄膜光催化剂制备过程机理探讨...............................................17

3.1 反应物浓度对Mn² 修饰TiO₂纳米薄膜光催化活性的影响.....................................17

3.2 PH对Mn² 修饰TiO₂纳米薄膜光催化活性的影响....................................................17

3.3 反应温度对Mn² 修饰TiO₂纳米薄膜光催化活性的影响.........................................18

3.4 反应时间对Mn² 修饰TiO₂纳米薄膜光催化活性的影响.........................................19