基于纳米氧化钛的乙醚催化发光性质及其分析应用研究

发布时间：2018-04-09 12:30

本文选题：催化发光　切入点：氧化钛　出处：《北京化工大学》2016年硕士论文

【摘要】：纳米氧化钛,作为一种在光电催化领域已被广泛深入研究的材料,具有存在稳定、容易获得且绿色无毒的特性。纳米氧化钛的电子结构、几何构型以及结构缺陷都会影响其催化性能,其中氧空位缺陷被认为具有突出的研究意义。目前,用于评价氧空位的方法很多,如拉曼光谱、电子顺磁光谱、扫描隧道显微镜等。但这些评价方法成本高、需要专业技术人员操作,因此,开发简单、快速、易普及的方法用于氧空位的评价十分必要。催化发光是气体分子在催化剂表面发生多相催化氧化反应时产生的发光现象,具有信号响应快、设备简单、容易操作等优点。本课题基于乙醚的催化发光信号强度依赖于氧化钛表面氧空位含量的特性,建立了一个以乙醚分子为探针,简单快速的评价纳米氧化钛中氧空位的催化发光分析方法。此外,控制合成了比表面积较大的介孔纳米氧化钛,将其应用于乙醚的催化发光分析上,通过调控不同易挥发有机物的波长检测范围,实现了对乙醚的高选择性检测。具体研究结果分为以下两部分：1、利用乙醚在纳米氧化钛表面发生催化发光反应产生的信号与纳米氧化钛表面氧空位量的正相关性,建立了一个以乙醚为催化发光探针简单、快速筛选纳米氧化钛中氧空位的新方法。研究表明,乙醚在纳米氧化钛表面的催化发光信号强度依赖于催化剂表面吸附氧的含量,而纳米氧化钛催化剂表面的氧空位有利于更多的氧气吸附。据此,推导出了乙醚在纳米氧化钛表面发生催化发光反应的合理过程。2、成功建立了基于介孔纳米氧化钛的高选择性乙醚催化发光传感器。使用具有介孔结构的纳米氧化钛为催化剂,通过控制不同易挥发有机物光谱波长的检测范围在440 nm左右,实现了对乙醚的高选择性检测,同时对乙醚高选择性检测的机理进行了研究。在介孔纳米氧化钛孔径、催化反应温度及载气流速最优的实验条件下,乙醚的最低检出限为1.5 mM,线性检测范围为2.0～50.0 mM。利用此乙醚-介孔纳米氧化钛催化发光传感器分别对香水样品和人工配制样品中的乙醚含量进行了检测,均得到满意的回收率,与标准气相色谱-质谱联用方法结果一致。
[Abstract]:Nanometer titanium oxide, as a widely studied material in the field of photocatalysis, has the characteristics of stable, easy to obtain and green non-toxic.The electronic structure, geometric configuration and structural defects of nanosized titanium oxide will affect their catalytic performance, among which oxygen vacancy defects are considered to be of great significance.At present, there are many methods for evaluating oxygen vacancies, such as Raman spectroscopy, electron paramagnetic spectroscopy, scanning tunneling microscope and so on.But the cost of these evaluation methods is high and they need professional technicians to operate. Therefore, it is necessary to develop a simple, rapid and easily popularized method for evaluating oxygen vacancy.Catalytic luminescence is a kind of luminescence produced by heterogeneous catalytic oxidation reaction of gas molecules on the surface of catalyst. It has the advantages of fast signal response, simple equipment and easy operation.Based on the characteristic that the intensity of catalytic luminescence signal of ether depends on the oxygen vacancy content on the surface of titanium oxide, a simple and fast method for the determination of oxygen vacancy in titanium oxide by using ether molecule as probe is established.In addition, the mesoporous nano-titanium oxide with large specific surface area was synthesized and applied to the catalytic luminescence analysis of ether. By regulating the wavelength detection range of different volatile organic compounds, the high selectivity detection of ether was achieved.The results are divided into the following two parts: 1. Using the positive correlation between the signal produced by the catalytic luminescence reaction of ether on the surface of nanometer titanium oxide and the amount of oxygen vacancy on the surface of nanometer titanium oxide, a simple probe using ether as the catalytic luminescent probe is established.A new method for rapid screening of oxygen vacancies in nanometer titanium oxide.The results show that the intensity of catalytic luminescence signal of ether on the surface of nano-titanium oxide depends on the amount of oxygen adsorbed on the surface of the catalyst, while the oxygen vacancy on the surface of nano-titanium oxide catalyst is favorable for more oxygen adsorption.Based on this, a reasonable process of catalytic luminescence reaction of ether on the surface of nanometer titanium oxide was deduced, and a highly selective ether catalyzed luminescence sensor based on mesoporous nanometer titanium oxide was successfully established.Using nanometer titanium oxide with mesoporous structure as catalyst, the high selectivity detection of ether was realized by controlling the detection range of spectral wavelength of different volatile organic compounds at about 440 nm.At the same time, the mechanism of high selectivity detection of ether was studied.Under the optimum experimental conditions of mesoporous nanometer titanium oxide pore size, catalytic reaction temperature and carrier airflow velocity, the detection limit of ether is 1.5 mm, and the linear detection range is 2.0 ~ 50.0 mm.The content of ether in perfume samples and artificially prepared samples was determined by using the ether mesoporous nano-titanium oxide catalytic luminescence sensor. The satisfactory recovery rate was obtained, which was consistent with the results of standard gas chromatography-mass spectrometry (GC-MS).
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O643.3;O657.3

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