rGO-ZnO基纳米纤维的制备及其气敏性能研究

发布时间：2018-02-28 02:14

  本文关键词： 气体传感器 复合材料 ZnO纳米纤维 还原氧化石墨烯 气敏性能　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：气体传感器作为检测气体成分及浓度的重要工具在众多领域扮演着十分重要的角色,金属氧化物半导体传感器因价格低廉、灵敏度高、响应速度快等优点而受到了众多科研工作者的青睐,其中拥有宽禁带宽度、大激子束缚能的ZnO纳米材料是一种优良的气敏材料,被广泛应用于气体传感器的研究中。然而,单一的ZnO气敏材料工作温度高、选择性差的问题仍然需要改进。自新型碳单质石墨烯被发现后,因其优良的性能和潜在的应用前景受到了广泛的关注。本文将以ZnO纳米纤维为基础材料,通过与微量石墨烯复合以及金属掺杂来提高气敏性能,具体研究工作如下:1.利用静电纺丝法制备ZnO纳米纤维,rGO(还原氧化石墨烯)与ZnO的复合通过两种方法进行制备,一是将煅烧后的ZnO纳米纤维与rGO溶液通过水热法制备,二是ZnO纺丝前驱体溶液中,直接加入适量的rGO,经纺丝煅烧后直接获得rGO/ZnO复合纳米纤维。研究表明,通过二步水热法及静电纺丝法获得的rGO-ZnO复合纳米纤维对H2S的气敏性能均有明显的提高。在200℃的工作温度下,rGO修饰ZnO纳米纤维对1ppmH2S气体的灵敏度可达6.8,是ZnO纳米纤维的2.7倍,而rGO/ZnO复合纳米纤维对1ppmH2S气体的灵敏度可达到20.6,是ZnO纳米纤维的8.2倍。且在同一温度下两种复合材料对其他干扰气体的灵敏度没有明显提高,说明通过二步水热法和直接纺丝获得的复合气敏材料其选择性均有明显提高。2.研究了rGO与Cu掺杂ZnO复合纳米纤维的气敏性能。采用二步水热法和静电纺丝直接复合两种方式分别制备了rGO修饰Cu掺杂ZnO纳米纤维和rGO/Cu掺杂ZnO复合纳米纤维,测试了材料的气敏性能。结果表明,rGO修饰Cu掺杂ZnO纳米纤维在200℃下,对1ppm H2S气体灵敏度可达到43。而rGO/Cu掺杂ZnO复合纳米纤维在工作温度为100℃时对1ppm的H2S的灵敏度可高达169,比Cu掺杂ZnO纳米纤维的灵敏度提高了57倍,比ZnO纳米纤维的灵敏度提高了66倍,并且r GO/Cu掺杂ZnO复合气敏材料的最佳工作温度相比ZnO纳米纤维及rGO修饰Cu掺杂ZnO纳米纤维均明显降低,说明通过静电纺丝复合rGO的方法更大程度的优化了气敏性能。3.研究了rGO与In掺杂ZnO复合纳米纤维的气敏性能。采用二步水热法和静电纺丝直接复合两种方式分别制备了rGO修饰In掺杂ZnO纳米纤维和rGO/In掺杂ZnO复合纳米纤维。通过SEM表面形貌测试发现,In的掺杂改变了ZnO纳米纤维的表面形貌,在Zn O纳米纤维表面均匀分布着直径极小的In2O3纳米棒。气敏特性测试表明,通过静电纺丝法制备出的rGO/In掺杂ZnO纳米纤维在200℃时,对10ppm的NO气体灵敏度为30。通过水热法制备出的rGO修饰In掺杂ZnO纳米纤维的最佳工作温度为150℃,比In掺杂ZnO纳米纤维的最佳工作温度降低了50℃,在此温度下对10ppm的NO气体灵敏度为36,是ZnO纳米纤维灵敏度的30倍。
[Abstract]:As an important tool for detecting gas composition and concentration, gas sensors play a very important role in many fields. Metal oxide semiconductor sensors have low price and high sensitivity. ZnO nanomaterials with wide band gap and high exciton binding energy are one of the excellent gas sensing materials, which have been widely used in the research of gas sensors, however, because of their fast response speed and so on, the ZnO nanomaterials with wide band gap and high exciton binding energy are widely used in the research of gas sensors. The problems of high temperature and poor selectivity of single ZnO gas sensing materials still need to be improved. Because of its excellent properties and potential application prospects, ZnO nanofibers will be used as the basic materials to improve the gas sensitivity by combining with trace graphene and doping metal. The specific research work is as follows: 1. The composite of ZnO nanofibers rGOand ZnO was prepared by electrospinning method. The first method was to prepare the calcined ZnO nanofibers with rGO solution by hydrothermal method. Secondly, the ZnO composite nanofibers were obtained by adding appropriate amount of rGOinto the solution of ZnO spinning precursor directly after spinning and calcining. The gas-sensing properties of rGO-ZnO nanofibers obtained by two-step hydrothermal method and electrostatic spinning method were improved obviously. The sensitivity of ZnO nanofibers modified by ZnO at 200 鈩，

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