论文总字数：18648字

摘 要

众所周知，TiO₂光催化氧化作用作为一种去除有机物的有效方法广泛应用于水和空气的清洁净化领域。TiO₂具有还原能力强，廉价，无毒和物理化学性质稳定等优点备受人们关注。但在实际使用中，纳米级TiO₂粉末虽具有较高的降解效率，但存在粉末分离回收困难且易失活等问题，限制了其实际应用^[1]。制备负载型纳米TiO₂光催化剂，利用吸附剂的大比表面积、强吸附性能和催化剂载体功能，既可以解决催化剂分离回收的难题，还可以克服催化剂颗粒易团聚和稳定性差的缺点。通过一定方法使吸附剂与TiO₂复合，提高目标污染物与光催化剂TiO₂的接触频率，可以在载体-TiO₂复合物表面产生一个底物富集环境，以提高对污染物的去除效率。本文在查阅大量文献的基础上，以金属有机骨架材料MOFs为模板，通过醇热法将纳米级TiO₂催化剂负载于吸附剂上，研究了吸附剂类型、TiO₂光催化性能的影响，分析了复合材料的结构与其性能之间的构效关系^[2-3]。

目前最常规的MOFs合成方法为水热法，但是这种方法耗时较长（8 h到数日的结晶时间），采用微波消解的方法合成MOFs不仅能大大缩短反应时间，产物的孔径分布也更为集中。目前MOFs作为新兴的多孔材料出现不久，人们对其的系统性研究仍远远不够^[4-5]。

本文采用微波消解法合成MOFs多孔纳米材料，探讨反应温度对产物的影响。实验分别以150 ℃、170 ℃和190 ℃为反应温度对MOFs多孔材料的最佳合成反应温度进行了探究。借助XRD等手段表明170 ℃合成的MOFs纳米材料相比于150 ℃和190 ℃具有较大的比表面积、较高结晶度、完好的结构。

利用醇热法成功制备了TiO₂@MOFs吸附-光催化纳米复合材料。本实验研究了TiO₂@MOFs纳米复合材料在365 nm紫外光激发下对有机废水甲基橙的吸附降解性能；同时研究了日光下对甲基橙的降解率。实验结果表明170 ℃的MOFs材料为核的TiO₂@MOFs吸附-光催化纳米复合材料紫外及日光催化性能最佳。

关键词：金属有机骨架材料MOFs TiO₂@MOFs复合材料 光催化

Abstract

As we all know, TiO₂ photocatalytic oxidation has been widely applied in the water and air cleaning sector as an effective way to remove the organic compound. TiO₂ enjoys the advantages of high reducing power, cheap, non-toxic and stable physical, chemical property, which have made this material enjoys much attention. But in the real application process, nanometer level TiO₂ powder has relatively higher degradation efficiency, and it has some problems like hard to separate and easy to lose its activity, which have limited its real application. Prepare the supported nanometer TiO₂ photocatalytic oxidation, by taking advantages of large proportion surface, strong absorbing performance and strong absorbing ability and catalyzed conveyor function, it can solves the difficult separation and recycle problems, it can overcome the shortcoming of easy to cluster and low stability degree. Recombine the adsorbent and TiO₂ by using certain methods and improve the target pollutants` contact frequency with TiO2 photocatalytic oxidation, it can generates a substrate concentration environment on the surface of carrier- TiO₂ compound, thus to improve the pollutants removing efficiency. This paper based on the large number of literature research, takes metal organic frameworks MOFs as mode, loads the nanometer TiO₂ photo-catalyst by using alcohol thermal method, it has studied the categories of adsorbent, TiO₂ photo-catalyst performance, it also analyzed the structure of the compound material and its structure-activity relation with its performance. This passage mainly started the following parts:

Currently, the most common MOFs compound method is hydrothermal, but this method is time-consuming(8 h- several days), synthetise MOFs by using microwave can not only shorten the reaction time, but the distribution of pore size of the products are also more centralized. Currently, it is not a very long time after the MOFs come out as a emerging cellular material, people`s systematic study in this regard is far from enough.

This paper synthetise MOFs cellular nanometer material by microwave digestion method

to explore the reaction temperature`s effect to the products. The experiment conducts an exploration about the best reaction temperature of MOFs cellular material, taking 150 ℃, 170 ℃, 190 ℃ as the reaction temperature respectively. By taking advantage of XRD and other measures, the results have shown that the MOFs nanometer material generated in170 ℃ environment have greater surface area, higher crystallinity and better structure compared to those generated under the 150 ℃ and 190 ℃.

Prepare the new-type channel MOFs nanometer absorbing material by using microwave digestion, and successfully prepared the TiO₂@MOFs adsorbent-photocatalysis nanometer compound material. This experiment studied TiO₂@MOFs absorbing-nanometer compound material`s absorbing degrading function to organic waste water helianthin B under the simulation of 365 nm ultraviolet light; at the same time, it has studied the degradation rate of helianthin B in the sunlight, the results suggest that the TiO₂@MOFs adsorbent-photocatalysis nanometer compound material MOFs material in 170 ℃ as the core has the best sunlight photocatalysis performance.

Key Words: Metal organic frameworks MOFs; TiO₂@MOFs compound material; photocatalysis

目 录

摘 要 I

Abstract II

第一章 前言 1

1.1 研究背景 1

1.2 有机污染消除方法 1

1.2.1 吸附法 1

1.2.2 光催化法 2

1.3 金属有机骨架材料概述 3

1.4 半导体光催化技术概述 3

1.5 TiO₂@MOFs杂化材料概述 5

1.6 研究方法和内容 7

第二章 实验部分

2.1 试剂与设备 8

2.2 吸附-光催化杂化材料的制备 9

2.2.1 MOFs的制备过程 9

2.2.2 温度对MOFs合成的影响 10

2.2.3 TiO₂@MOFs杂化材料的制备过程 10

第三章 结果与讨论 12

3.1 MOFs的XRD分析 12

3.2 MOFs吸附性能研究 12

3.3 TiO₂@MOFs杂化材料吸附性能研究 13

3.4 TiO₂@MOFs杂化材料光催化性能研究 14

3.4.1 TiO₂@MOFs杂化材料可见光光催化活性 14

3.4.2 TiO₂@MOFs杂化材料紫外光光催化活性 15

第四章 结论与展望 17

4.1 结论 17

4.2 展望 17

参考文献 18

致谢 21

第一章 前言

1.1 研究背景

请支付后下载全文，论文总字数：18648字