介孔TiO纳米粉体制备、掺杂改性及其光催化性能研究

摘要

Mesoporous TiO2 materials have great application values in wastewater treatment and air purification because of its high photocatalyti properties．However,Mesoporous TiO2 photocatalyst has lower quantum yield and lower visible—light utilization ratio．To this problem，in this paper，advantages and disadvantages of mesoporous TiO2 photocatalyst which was prepared by hydrolysis precipitation method and Sol-Gel method we compared．Mesoporous TiO2 photocatalyst was prepared by hydrolysis precipitation method and doped modification．It put forward one-element or two-element doped modification method to improve the property of mesoporous TiO2 photocatalyst with transition metal ions as doping agent or rare earth ions．T crystal phase，microstructure，photocatalytic properties of the prepared mesoporous TiO2 were characterized by X—ray diffraction(XRD)，N2 adsorption-desorption isotherm，transmission electron microscopy(TEM)，Ultraviolet—Visible absorption spectrum，infrared spectrum．The influences of doped other ions to microstructure and properties of Mesoporous TiO2 were investigated．The photocatalytic properties of mesoporous TiO2 in the degradation of methyl orange solution were determined．The effect of different molar ratio of doped agent，heat treatment temperature and concentrations of TiO2 to properties of one-element or two-element doped mesoporous TiO2 were also studied．The photocatalytic properties of mesoporous TiO2 were improved．The effect of different doped elements was investigated in the one--element or two-element doped system．The results showed that after heat treatment temperature at 500℃ tetragonal anatase phase structure was formed in the mesoporous TiO2 photocatalyst which was prepared by hydrolysis precipitation method or Sol—Gel method．And the temperature(500℃)was considered the best heat treatment temperature of the mesoporous TiO2．The optimal concentration of the mesoporous TiO2 was .0 g-L-1．Photocatalytic decomposing rate of methyl orange solution were 100％and 90％respectively．Before and after heat treatment，the photo absorption performance of mesoporous TiO2 was measured by Ultraviolet—Visible absorption spectrum，and the bondings in mesoporous TiO2 and the changes were discussed by infrared spectrum．It indicated that absorption wavelength range of mesoporous TiO2 was obvious redshift after he treatment．Absorption area was obviously increased in the visible region．Solar energy utilization efficiency was significantly improved．One-element(Co，Fe or Ce)doped mesoporous TiO2 photocatalyst were prepared respectively by hydrolysis precipitation method．The particle size and phase transformation process of one-element doped mesoporous TiO2 were controlled by changing heat treatment temperature．The one—element doped mesoporous TiO2 possesses high specific surface area，high purity,narrow pore size distribution and high thermal stability．The best heat treatment temperature of the mesoporous TiO2 was 500℃．The optimal concentration of the doping agent were 0.1，0．05 and 0．05 mol％ respectively．Photocatalytic decomposing rate of methyl orange solution were up to 90，99 and 94％respectively． Two-element(Co，Ce)doped mesoporous Ti photocatalyst was prepared by hydrolysis precipitation method．The particle size and phase transformation process of(Co，Ce)doped mesoporous TiO2 were controlled by changing heat treatmenttemperature．(Co，Ce)dop mesoporous TiO2 was high thermal stability．The best heat treatment temperature of the mesoporous TiO2 was 500℃．The optimal concentration of the doping agent was 0．1 Comol％and O．05Cemol％ respectively．Photocatalytic decomposing rate of methyl orange solution was up to 90％．In th paper,Mesoporous TiO2 nano-powder was successfully obtarined by tetrabutyl titanate as raw materials and one—element or two-element were doped in the mesoporous TiO photocatalyst．The thermal stability and photocatalystic properties of mesoporous TiO2 nano-powder increased obviously.

目录

英文文摘

论文说明：图表目录

声明

致谢

第一章绪论

1.1引言

1.2介孔材料概述

1.2.1介孔材料定义

1.2.2介孔材料分类

1.2.3介孔材料研究背景及研究现状

1.3介孔TiO2材料合成机理

1.3.1液晶模板机理(Liquid crystal templating mechanism,简写：LCT)

1.3.2广义液晶模板机理(Generalized liquid crystal templating mechanism)

1.3.3协同作用机理(Cooperative formation mechanism,简记为CFM)

1.4介孔TiO2粉体的光催化原理

1.5介孔TiO2的应用

1.5.1介孔TiO2光催化剂

1.5.2介孔TiO2作电极膜材料

1.5.3介孔TiO2的其他用途

1.6介孔TiO2材料的前景展望及存在的问题

1.6.1前景展望

1.6.2存在的问题

1.7本文研究的目的和内容

第二章介孔TiO2纳米粉体制备的工艺条件及其表征

2.1制备介孔TiO2纳米粉体的工艺条件

2.1.1实验原料与仪器

2.1.2实验过程

2.2光催化活性的测定

2.3 TiO2光催化性质的主要影响因素

2.3.1催化剂

2.3.2光源和光强

2.3.3 pH值

2.4介孔TiO2材料的表征

2.4.1 X射线衍射

2.4.2低温气体吸附技术

2.4.4 TEM分析

2.4.5紫外-可见光漫反射吸收光谱(UV-vis)

2.4.6红外光谱

2.5本章小结

第三章介孔TiO2纳米粉体的制备及其组织结构表征

3.1介孔TiO2粉体光催化剂

3.2水解沉淀法制备介孔TiO2粉体光催化剂

3.2.1样品制备

3.2.2结果与讨论

3.3溶胶-凝胶法制备介孔TiO2光催化剂

3.3.1溶胶-凝胶法的反应机理

3.3.2溶胶-凝胶法制备过程

3.3.4结果与讨论

3.4水解沉淀法与溶胶-凝胶法的比较

3.5本章小结

第四章一元掺杂介孔TiO2纳米粉体的制备及光催化性能研究

4.1前言

4.2金属Co掺杂介孔TiO2光催化剂的制备及其光催化性能研究

4.2.1样品制备

4.2.2结果与讨论

4.3金属Fe掺杂介孔TiO2光催化剂的制备及其光催化性能研究

4.3.1样品制备

4.3.2结果与讨论

4.3.3过渡金属离子掺杂光催化剂机制

4.4稀土元素Ce掺杂介孔TiO2光催化剂的制备及其光催化性能研究

4.4.1样品制备

4.4.2结果与讨论

4.4.3稀土元素掺杂影响光催化降解机理

4.5本章小结

第五章Co、Ce共掺杂介孔TiO2纳米粉体的制备及其光催化性能研究

5.1引言

5.2样品制备

5.3结果与讨论

5.3.1结构表征

5.3.2样品的N2吸附-脱附曲线孔径分布分析

5.3.3透射电镜(TEM)分析

5.3.4金属Co掺杂浓度对光催化性能的影响

5.3.5稀土Ce掺杂量对TiO2光催化活性的影响

5.3.6热处理温度对光催化性能的影响

5.4本章小结

第六章全文总结

6.1总结

6.2工作展望

参考文献

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