论文总字数：25183字

摘 要

气体传感器广泛应用于环境监测、工业生产监控、医疗、食品安全检验及军事安全方面等各个领域。其中敏感层材料使气体传感器的核心部件，围绕着敏感层材料的选择和构型展开研究是开发出新型高性能气体传感器的重点。MoO₃材料作为当前气敏领域研究的热点，具有较高的灵敏度、较好的选择性和高化学稳定性。MoO₃独特的层状结构使其气敏材料领域表现出极大的实用性和发展潜力。然而传统MoO₃薄膜材料对低浓度的气体的感测能力（低于10 ppm）较低、工作温度过高（300到500 ℃左右）、响应/恢复时间长，并且不易制作微型器件，这些问题带来的使用安全隐患、工作能能耗较高和应用领域受限都制约着其规模化市场应用。因此需要对MoO₃材料进行合适的改性，本文通过研究Cu掺杂的一维MoO₃纳米带材料，来尝试解决上述问题。

本文采用水热法制备了Cu掺杂MoO₃纳米带材料。利用FESEM和氮气等温吸脱附对所制备材料进行了表征，以探究Cu掺杂对MoO₃纳米带材料形貌和结构上的影响。制备了基于Cu掺杂MoO₃纳米带材料的气体传感器并对其进行氨气的气敏性能测试，探究了Cu掺杂对MoO₃纳米带材料的气敏性能的影响并进一步总结分析Cu掺杂在MoO₃纳米材料的气敏过程中发挥地作用。

研究结果表明：

1. 通过水热法制备的Cu掺杂MoO₃纳米带材料长度约为1 μm，宽度约为150 nm，边缘呈现出不规则的锯齿状结构。

2. 基于Cu掺杂MoO₃纳米带材料制备的气体传感器在240 ℃对5-1000 ppm的NH₃具有良好的响应。其在最佳工作温度150 ℃下，在10 ppm的NH₃气体浓度下灵敏度为1.34，1000 ppm的NH₃气体浓度下灵敏度为5.11。相对于纯MoO₃纳米带材料，在对低浓度NH₃的感测能力和降低工作温度能力方面都有不同程度的提升。

3. Cu掺杂MoO₃纳米带材料的气敏性能之所以有一定幅度地提升，这是由于：（1）MoO₃纳米带材料的尺寸显著减小，使得材料比表面积增加；（2）Cu掺杂不仅使得MoO₃材料的表面氧空位浓度增加，同时还提升了材料表面化学吸附氧的含量；（3）Cu² 离子作为反应活性位点吸附NH₃分子，可以与之形成稳定的配合物离子。从而提高对NH₃的催化分解能力。

本文的特色：MoO₃材料独特的层状结构使其在气敏领域表现出巨大的潜力，而传统的MoO₃材料的种种缺点制约着其规模化市场应用。通过对其进行适当的改性，包括形貌尺寸调控和掺杂等能大大提高MoO₃材料的气敏性能，同时对其气敏机理进行更加深入探究和阐述，为MoO₃材料在气敏领域的进一步推广和应用具有重要的意义。

关键词：MoO₃；一维纳米材料；Cu掺杂；气敏机理

Abstract

Gas sensors are widely used in environmental monitoring, industrial production monitoring, medical treatment, food safety inspection, military safety and other fields. Among them, the sensitive layer material is the core component of gas sensor. The research on the selection and configuration of the sensitive layer material is the key to develop a new high-performance gas sensor. MoO₃ material, as a hot spot in the field of gas sensing, has high sensitivity, good selectivity and high chemical stability. The unique layered structure of MoO₃ makes its gas sensing material field show great practicability and development potential. However, the traditional MoO₃ thin film materials have low sensing ability (less than 10 ppm) for low concentration gas, high operating temperature (300-500 ℃), long response / recovery time, and are not easy to make micro devices. These problems bring potential safety hazards, high energy consumption and limited application fields, which restrict its large-scale market application. Therefore, it is necessary to modify MoO₃ materials properly. In this paper, we try to solve the above problems by studying the Cu doped one-dimensional MoO₃ nanoribbons materials.

Cu doped MoO₃ nanoribbons were prepared by hydrothermal method. The prepared materials were characterized by FESEM and nitrogen adsorption isotherm to investigate the influence of Cu doping on the morphology and structure of MoO₃ nanoribbons. A gas sensor based on Cu doped MoO₃ nanoribbons material was prepared and tested for ammonia gas sensing performance. The influence of Cu doping on the gas sensing performance of MoO₃ nanoribbons material was explored and the role of Cu doping in the gas sensing process of MoO₃ nanoribbons material was further summarized and analyzed. The experimental contents and research results are as follows:

1. The length and width of Cu doped MoO₃ nanoribbons prepared by hydrothermal method are about 1 μ m and 150 nm respectively, and the edges of the nanoribbons show irregular zigzag structure.

2. The gas sensor based on Cu doped MoO₃ nanobelt material has a good response to 5-1000 ppm NH₃ at 240 ℃. At the optimum operating temperature of 150 ℃, its sensitivity is 1.34 to 10 ppm NH₃ gas concentration and 5.11 to 1000 ppm. Compared with pure MoO₃ nanobelts material, the sensing ability of low concentration NH₃ and the ability of reducing the working temperature are improved to some extent.

3. The reason why the gas sensing performance of Cu doped MoO₃ nanobelts material has been improved to a certain extent is that: (1) the size of MoO₃ nanobelts material is significantly reduced, which makes the specific surface area of the materials increase; (2) Cu doping not only makes the surface oxygen vacancy concentration of MoO₃ materials increase, but also increases the content of chemically adsorbed oxygen on the surface of the materials; (3) Cu² as the reactive active site Point adsorption of NH₃ can form stable complex ions with it. So as to improve the catalytic decomposition capacity of NH₃.

The unique layered structure of MoO₃ material makes it show great potential in the field of gas sensing, while the disadvantages of traditional MoO₃ material restrict its large-scale market application. The gas sensing performance of MoO₃ material can be greatly improved by appropriate modification, including morphology and size control and doping. At the same time, the gas sensing mechanism of MoO₃ material is further explored and elaborated, which is of great significance for the further promotion and application of MoO₃ material in the field of gas sensing.

Key Words：MoO₃；one-dimensional nano materials；Cu doped；gas sensing

目录

第1章 绪论 1

1.1 气体传感器概述 1

1.1.1 气体传感器的分类 1

1.1.2 气体传感器的性能指标 2

1.1.3 气体传感器的研究现状 2

1.2 一维纳米材料简介 3

1.2.1 一维纳米材料的分类 3

1.2.2 一维纳米材料的制备方法 3

1.3 MoO₃材料概述 4

1.3.1 MoO₃的结构与性质 4

1.3.2 MoO₃纳米材料气敏机理 5

1.3.3 MoO₃材料在氨气体传感器的应用 5

1.3.4 MoO₃的改性 6

1.4 论文的研究意义和研究内容 8

第2章 Cu掺杂MoO₃纳米带材料的制备与表征方法 9

2.1材料与器件的制备 9

2.1.1 实验所需试剂及仪器 9

2.1.2 Cu掺杂MoO₃纳米带材料的制备方法 10

2.1.3 基于Cu掺杂MoO₃纳米带的气体传感器的制备方法 10

2.2 Cu掺杂MoO₃纳米带材料的表征方法 11

2.2.1 材料的结构、形貌表征方法 11

2.2.2 材料的气敏性能表征方法 11

第3章 Cu掺杂MoO₃纳米带材料的结构及气敏性能 14

3.1 Cu掺杂MoO₃纳米带材料的结构与形貌表征分析 14

3.2 Cu掺杂MoO₃纳米带材料的气敏性能表征分析 15

3.3 Cu掺杂MoO₃纳米带材料的气敏机理研究 17

3.4 本章小结 18

第4章 结论与展望 20

参考文献 21

致谢 24

附录 25

第1章 绪论

• • 1. 气体传感器概述

在科技不断进步的当今社会，世界工业化进程也在逐渐加深，在工业生产过程中难免会发生各种各样的气体泄漏事故，这其中不乏易燃易爆和有毒有害气体，这将对人们的生命安全、环境和财产安全都造成严重的威胁。因此对这些气体进行快速而准确地监测是非常必要的。

气体传感器是能与气体之间发生相互作用，并将气体的种类和浓度等定性或定量的信息转化为可识别信号的装置。如今广泛应用于环境监测、工业生产监控、医疗、食品安全检验及军事安全方面等各个领域。1962年，日本学者Siyama^[1]首先报道了金属氧化物的气敏效应，并制造出了第一个以ZnO为材料的气体传感器。随着越来越多学者的深入研究，气体传感器领域开始迅速发展起来。

• • • 1. 气体传感器的分类

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