【作者】 苏畅；

【导师】 刘丽；

【作者基本信息】 吉林大学 ， 无线电物理， 2016， 硕士

【摘要】 近几年,随着中国工业的飞速发展,环境污染问题越来越受到人们的关注。监控检测室内外易燃易爆有毒气体在人们的日常生产生活中起着重要的作用。因此研究和开发监控检测这些有害气体的传感器成为热门课题,而气体传感器的核心之一部分是气敏材料,气敏材料的种类和结构对气体传感器的性能有着至关重要的影响。当前,随着纳米材料的发展,低维、多孔的纳米气敏材料成为人们研究的一个重要方向。研究表明,多孔一维纳米材料具有较高的比表面积,电子有向传导等优点,这些优点对材料的灵敏度有着巨大影响。Fe₂O₃是一种常见的、廉价的、具有良好的物理化学性质的半导体材料,其在电池、催化剂、光电解、磁存储以及气体传感器等领域有着广泛的应用。尤其近几年,Fe₂O₃已经被用作气敏材料来检测多种气体。然而,纯的Fe₂O₃材料的气敏性能较差,并不能满足人们的要求。所以研究者通常将Fe₂O₃低维化、造孔和掺杂其他元素来提高其气敏性能。本文利用静电纺丝的实验方法合成一维Fe₂O₃半导体纳米材料。通过调控前驱溶液中各个材料的比例和掺杂其他材料来获得具有良好气敏性能的不同形貌和掺杂的一维纳米半导体Fe₂O₃气敏材料,进而制作性能优异的气体传感器件。具体内容如下:1.用静电纺丝法制备直径约90nm的纯的和掺杂不同比例Sm的一维纳米管形貌的半导体Fe₂O₃材料,并基于该材料制作气体传感器,研究了它们的气敏性能。研究表明掺杂Sm显著地提高了纯的纳米管Fe₂O₃材料对丙酮气体的灵敏度。在最佳工作温度240℃下,掺杂3wt%Sm的纳米管Fe₂O₃材料对50ppm的丙酮气体的灵敏度为33,是纯的纳米Fe₂O₃材料的13倍。并且掺杂3wt%Sm的Fe₂O₃纳米管传感器对丙酮具有较低的检测极限,为500ppb,相对应的灵敏度为2.3。此外,掺杂3wt%Sm的Fe₂O₃纳米管传感器具有良好的选择性和长期稳定性。2.通过静电纺丝法制备直径约80nm的纯的和掺杂Nd的一维纳米多孔管形貌的半导体Fe₂O₃材料,并制作基于它们的传感器件,对其气敏性能进行了测试。结果表明掺杂Nd的纳米多孔管Fe₂O₃传感器对丙酮气体具有超高的灵敏度。在最佳工作温度240℃下,其对50ppm丙酮气体的灵敏度达到44,是纯的一维纳米管Fe₂O₃传感器的17倍。并且该传感器还具有优异的选择性和长期稳定性。3.通过静电纺丝法制备了纯的以及掺杂Al₂O₃的一维纳米管半导体Fe₂O₃材料,制作了基于它们的传感器,并对传感器的气敏性能进行了检测。结果显示纯的纳米管Fe₂O₃材料对乙醇气体的气敏性能由于Al₂O₃的掺入有了极大的提高。在240℃的最佳工作温度下,掺杂Al₂O₃的一维纳米管Fe₂O₃传感器对50ppm的乙醇的灵敏度为41.8,并且在最低检测浓度300ppb时的灵敏度为2。相对应的纯的纳米管Fe₂O₃传感器的灵敏度为4。此外,掺杂Al₂O₃的纳米管Fe₂O₃传感器具有良好的选择性和长期稳定性。4.通过静电纺丝法合成了纯的和掺杂Pr的一维纳米管形貌的半导体Fe₂O₃材料,制作了基于它们的气体传感器,并研究其气敏性能。结果显示掺杂Pr的纳米管Fe₂O₃传感器比纯的纳米管Fe₂O₃传感器对乙醇气体具有更好的气敏性能。掺杂Pr的纳米管Fe₂O₃传感器在240℃的最佳工作温度下对10ppm的乙醇的灵敏度为21.3,并且能检测到300ppb乙醇,相对应的灵敏度为2.1。纯的纳米管Fe₂O₃传感器对10ppm乙醇的灵敏度为1.5。此外掺杂Pr的纳米管Fe₂O₃传感器具有良好的选择性和长期稳定性。更多还原

【Abstract】 In the recent years, the pollution of environment problem attracts more and more attentions with the rapid developing of Chinese industry. Monitoring the inflammable,explosive and toxic gases plays a very important role in peoples’ life. Hence, the research and development of gas sensors for monitoring these harmful gases became a hot topic. One of the important part of gas sensors is gas sensing material, and the species and structures of the gas sensing materials have a crucial influence on the performance of gas sensors. At present, low dimension and porous gas sensing nanomaterials became a hot topic with the development of nanomaterials. The studies have indicated that porous one-dimension nanomaterials have a high specific area and electronics conduction properties. And these advantages are benefit to gas sensing properties. Fe₂O₃ is a common, cheap and good physicochemical property semiconductor material. And it has been widely used in the fields of battery, catalyst,photoelectric solution, magnetic, gas sensor and so on. In the recent years, Fe₂O₃ has been used in gas sensors to test many gases. However, pure Fe₂O₃ has a poor gas sensing property, and couldn’t meet people’s requirements. So researchers usually make Fe₂O₃ a low dimension, pore and doping to improve its gas sensing property.In this paper, one-dimension Fe₂O₃ nanomaterials are prepared via electrospinning method. In the mean of adjusting precursor solutions to obtain one-dimension Fe₂O₃ nanomaterials with good gas sensing property, different structure and doping. And the Fe₂O₃ nanomaterials are made for excellent performance of gas sensors. Specific content as follows:1 Pure and Sm-doped Fe₂O₃ nanotubes with a diameter 90 nm are prepared via a typical electrospinning technology. The nanomaterials are made for gas sensors, and the performances of the gas sensors are researched. The research indicate that the gas sensing properties of pure Fe₂O₃ nanotubes are improved bt doping Sm, remarkably.At the optimum operating temperature 240℃, the response of 3wt% Sm-doped Fe₂O₃ nanotubes is 33 to 50 ppm acetone, which is 13 times larger than that of pure Fe₂O₃ nanotubes. The lowest detection limit of acetone is 500 ppb to which the response is2.3. In addition, 3wt% Sm-doped Fe₂O₃ nanotubes exhibit good selectivity and long term stability.2 Pure and Nd-doped porous Fe₂O₃ nanotubes with a diameter 80 nm are prepared via a typical electrospinning technology. The nanomaterials are made for gas sensors, and the performances of the gas sensors are researched. The result shows that the Nd-doped porous Fe₂O₃ nanotubes performance a ultrahigh response to acetone.The response of Nd-doped porous Fe₂O₃ nanotubes is about 44 to 50 ppm acetone at the optimum operating temperature of 240℃, which is 17 times larger than that of pure porous Fe₂O₃ nanotubes. In addition, the Nd-doped porous Fe₂O₃ nanotubes possess good selectivity and long-term stability.3 Pure and Al₂O₃-doped Fe₂O₃ nanotubes are prepared via a typical electrospinning technology. The nanomaterials are made for gas sensors, and the performances of the gas sensors are researched. The research of the samples gas sensing properties demonstrates that the ethanol sensing properties of Fe₂O₃ nanotubes are enhanced by doping Al₂O₃, remarkably. The response value of Al₂O₃-doped Fe₂O₃ nanotubes to 50 ppm ethanol is 41.8 at the optimum operating temperature 240℃. And the lowest detection limit is 300 ppb, to which the response value is about 2. The response of pure Fe₂O₃ nanotubes is 4. In addition, the Al₂O₃-doped Fe₂O₃ nanotubes possess good selectivity and long-term stability.4 Pure and Pr-doped Fe₂O₃ nanotubes are prepared via a typical electrospinning technology. The nanomaterials are made for gas sensors, and the performances of the gas sensors are researched. The researches of the gas sensing properties of the samples show that Pr-doped Fe₂O₃ nanotubes possess a better sensitive to ethanol than that of pure Fe₂O₃ nanotubes, and the response value of Pr-doped Fe₂O₃ nanotubes to10 ppm ethanol is 21.3 at the operating temperature 240℃. And the lowest detection limit is 300 ppb, to which the response value is about 2.1. The response of pure Fe₂O₃ nanotubes is 1.5 to 10 ppm ethanol. Moreover, Pr-doped Fe₂O₃ nanotubes show goodselectivity and long-term stability.更多还原