基于一维金属氧化物纳米材料气敏特性的研究

发布时间：2018-03-03 23:08

本文选题：气体传感器　切入点：静电纺丝　出处：《吉林大学》2016年博士论文　论文类型：学位论文

【摘要】：中国国家标准第GB7665-87项中对传感器的定义为:“能感受规定的被测量并按照一定的规律转换成可用信号的器件或装置。”气体传感器是传感器的一个重要分支,它被广泛应用于大气/室内环境监测、污染源监控、工业/民生安全和非侵入式医疗等领域。为了拓展应用领域,气体传感器需要进一步提升响应值、选择性、响应恢复速度和可靠性。作为气体传感器的核心组成部分,敏感材料直接影响气体传感器的敏感特性,因此开发高性能的敏感材料是提升气体传感器性能的重要途径。近年来,随着静电纺丝技术的不断发展,通透性好、比表面积大的一维纳米材料引起人们的广泛关注。本论文以一维金属氧化物纳米材料的气敏特性为研究对象,从提高材料的识别功能、转换功能和敏感体的利用效率入手,通过掺杂其他半导体材料来调控其形貌和组成,从而提高气体传感器的响应值、选择性、响应恢复速度和长期稳定性。本文的具体研究内容如下:(1)利用静电纺丝技术制备了直径均一的WO3纳米线,并在此基础上制备了掺入了不同比例La2O3的WO3纳米线。气敏特性测试结果表明:样品中La3+与W6+的摩尔比为3%的纳米线对丙酮的响应值最高,对100ppm丙酮的响应值为12.7,约为未掺杂WO3纳米线的2倍。但该气体传感器恢复速度较慢,检测下限较高。(2)为进一步提高气体传感器对丙酮的响应值,利用静电纺丝技术制备了掺入不同比例In2O3的WO3纳米线。形貌表征结果显示:随着In2O3掺杂量的增加,纳米线表面变粗糙,颗粒边界变得明显。气敏特性测试结果表明样品中In2O3与WO3的摩尔比为1.5%的纳米线对丙酮的响应值最高,对50ppm丙酮的响应值为12.9,约为未掺杂WO3纳米线的2.5倍。此外,其检测下限大大降低,且具有较好的抗湿性。(3)利用静电纺丝法制备了多孔性Ni O中空纳米管,在此基础上制备掺杂W6+的Ni O中空纳米管。形貌表征结果显示利用静电纺丝法制备的纳米管的直径约90nm,且随着W6+掺杂量的增加,晶粒的尺寸逐渐减小,比表面积增大。气敏特性测试结果表明样品中W6+与Ni2+摩尔比为2%的纳米管对二甲苯的响应值最高,对200ppm二甲苯的响应值为8.7,约为未掺杂Ni O纳米管的3.3倍。然而,基于上述材料的气体传感器仍具有响应时间和恢复时间较长、检测下限较高、响应值较小等不足。(4)为进一步提高气体传感器对二甲苯的响应值,利用静电纺丝法制备了不同比例的Cr3+掺杂Ni O中空纳米管。气敏特性测试结果表明Cr3+/Ni2+掺杂比例为3 mol%的样品对二甲苯的响应值提高显著,对50ppm二甲苯的响应值为88,约为未掺杂Ni O纳米管的63倍。与W6+掺杂Ni O纳米管的气敏特性相比,Cr3+掺杂Ni O纳米管具有以下优点:一、响应值高,对200ppm二甲苯的响应值为695;二、响应和恢复速度快,其对200ppm二甲苯的响应时间为144s,恢复时间为50s;三、检测下限低,该气体传感器的检测下限为5ppm;四、选择性更好,分辨率D(Rxylene/Rethanol)为9。
[Abstract]:China national standard item GB7665-87 in the definition of the sensor is: "feelings can be measured under the law and in accordance with a certain signal can be converted into the device or device." gas sensor is an important branch of the sensor, which is widely used in atmospheric / indoor environment monitoring, monitoring of pollution sources, industrial / people's livelihood safe and non-invasive medical field. In order to expand the application field of gas sensors, the need to further enhance the response value, selectivity, response speed and reliability. As the core of the gas sensor part, sensitive materials directly affect the sensitivity of the gas sensor, so the development of high performance sensitive materials is an important way to enhance the performance of gas sensors. In recent years, with the continuous development of the electrospinning technique of good permeability, specific surface area of nano materials has attracted people's attention. This paper The gas sensing properties of one dimensional metal oxide nano materials as the research object, from improving the recognition function of the utilization efficiency of conversion function and sensitive body, by doping other semiconductor materials to control the morphology and composition, so as to improve the sensor response value, selectivity, response and recovery speed and long-term stability. The main research contents of this paper are as follows: (1) WO3 nanowires with uniform diameter were fabricated by electrospinning, WO3 nanowires was prepared based on the incorporation of different proportions of La2O3 and the test results. The gas sensing properties show that the mole ratio of La3+ to W6+ in the sample in response to the 3% nanometer line of acetone is highest. Response to 100ppm acetone was 12.7, about the undoped WO3 nanowires 2 times. But the slow recovery of gas sensor, the detection limit is higher. (2) to further improve the response to acetone gas sensor The value of WO3 nanowires were prepared by adding different proportions of In2O3 by electrospinning. The morphology characterization results show that with the increase of the concentration of In2O3, the nanowire surface becomes rough, the grain boundary becomes obvious. The test results show that the gas sensing properties of the molar ratio of In2O3 to WO3 in the sample in response to the 1.5% nanometer line of acetone the highest response to 50ppm acetone was 12.9, about the undoped WO3 nanowires 2.5 times. In addition, the detection limit is reduced greatly, and has good moisture resistance. (3) porous Ni O nanotubes were prepared by electrospinning, Ni nanotubes prepared W6+ doped O based on the morphology characterization results showed that the electrospinning of the nanotube diameter is about 90nm, and with the increase of W6+ content, the grain size decreases, the specific surface area increased. The test results showed that W6+ and Ni2+ gas sensing properties of friction in the sample The response ratio of the highest value of the 2% para nanotubes, response to xylene 200ppm value is 8.7, about 3.3 times as much as Ni doped O nanotubes. However, the gas sensor material is based on the response time and recovery time is longer, the detection limit is high, the response value of the deficiencies of smaller (4) to further improve. Sensor response of p-xylene value, Cr3+ doped Ni O hollow nanotubes in different proportions were prepared by electrospinning. The test results show that the response of the gas sensing properties of Cr3+/Ni2+ doping ratio of 3 samples of p-xylene mol% values provided by Gao Xian, 50ppm response to xylene was 88, about 63 times as much as Ni doped O nanotubes compared with the gas sensing properties of W6+ doped Ni O Cr3+ doped Ni nanotubes and O nanotubes has the following advantages: a higher response value, response to xylene 200ppm value is 695; two, response and recovery speed, the The response time to 200ppm xylene is 144s, the recovery time is 50s. Three, the detection limit is low, the detection limit of the gas sensor is 5ppm, four, the selectivity is better, and the resolution D (Rxylene/Rethanol) is 9..

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TP212;TB383.1

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