摘要：如今环境污染日益严重，气敏和光催化是以科技手段保护环境的重要方向：有机还原性气体的检测有利于保障人们生命安全，使用光催化技术降解有机染料有助于污水处理。CoTiO3是一种钛铁矿型金属氧化物，p型半导体，其纳米材料具有气敏和光催化性能，具有广阔的研究和应用前景。

采用溶胶凝胶法制备CoTiO3纳米颗粒和薄膜。利用X射线衍射仪，场发射扫描电子显微镜、紫外-可见分光计分析CoTiO3物相结构、微观形貌和光学性质。发现CoTiO3属于三方结构，菱面体晶胞，光学带隙2.1eV，颗粒平均直径100～150nm，使用乙二醇甲醚作溶剂或添加表面活性剂可以提高颗粒的分散性。

使用CGS-1TP气敏分析系统和高压汞灯-紫外可见分光计分别测试气敏和光催化性能。结果显示，CoTiO3纳米颗粒气敏性能优异，最佳工作温度可低至233℃，对50ppm酒精的灵敏度高达209，最短响应恢复时间仅5～10秒，且具有一定选择性和重复稳定性，灵敏度与浓度满足log(S-1)-logC线性关系。CoTiO3光催化性能良好，3小时对罗丹明B光催化降解89%，降解过程符合衰减动力学模型。

关键词：CoTiO3；纳米材料；气敏；光催化

Abstract：Environmental pollution is deteriorating nowadays. Gas sensing and photocatalysis are important aspects of environmental protection with scientific methods: detecting organic reductive gas is propitious to protect people’s health. Photocatalysis technology can be used to decompose organic dye, which helps to manage polluted water. CoTiO3 is a kind of ilmenite metallic oxide as well as p-type semiconductor. Its nano material has good properties of gas sensing and photocatalysis, which has broad prospects for study and application.

CoTiO3 nanoparticle and nano film were synthesized by sol-gel method. X-ray diffractometer, field emission scanning electron microscope and UV-vis spectrometer were used to analyze phase structure, microscopic morphology and optical properties of CoTiO3. It was found that structure of CoTiO3  belongs to trigonal system and rhombohedron unit

cell. Its optical band gap was 2.1eV, average particle diameter was 100～150nm. Using

solvent ethylene glycol monomethyl ether or adding surface active agent can increase dispersivity of CoTiO3 nanoparticles.

CGS-1TP gas sensing analysis system, high-voltage mercury lamp with UV-vis spectrometer were respectively used to test gas sensing and photocatalytic properties. Results indicated that CoTiO3 nanoparticles show great gas sensing property, its optimum operating temperature is as low as 233℃, sensitivity towards 50ppm at optimum operating

temperature can reach 209.  The shortest response-recovery time was  10～15s,    the    gas

sensor also has good selectivity and stability. About sensitivity and gas concentration, there exisits liner relation between log(S-1) and logC. CoTiO3 shows good photocatalytic ability, after 3 hours of UV-irradiation, its catalytic degradation rate towards RHB can reach 89%. The process of catalytic degradation corresponds to decay kinetic model.

Keywords: CoTiO3; nano material; gas sensing; photocatalysis

目录

摘要 I

Abstract II

第一章 绪论 1

1.1 引言.1

1.2 CoTiO3晶体结构1

1.3 CoTiO3气敏性能2

1.4 CoTiO3光催化性能3

1.5 本课题主要研究内容及意义.4

第二章 CoTiO3纳米材料制备和表征方法 5

2.1 制备方法.5

2.2 表征方法.6

第三章 CoTiO3制备、表征及性能 8

3.1 实验部分.8

3.2 材料表征结果分析12

3.3 气敏性能分析17

3.4 光催化性能分析24

第四章 原理探究 26

4.1 分散剂、溶剂对微观形貌的影响26

4.2 气敏机理27

4.3 光催化机理31

第五章 总结与展望 33

致谢 34

参考文献 35

本科期间取得的研究成果 38