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题名	氧化锌基甲醛气敏材料的制备与气敏性能研究
作者	韩宁
学位类别	博士
答辩日期	2010-06-06
授予单位	中国科学院研究生院
导师	陈运法
关键词	甲醛传感器 氧化锌 谱分析 晶体缺陷 电泳沉积工艺
其他题名	Preparation and characterization of ZnO-based sensor for formaldehyde gas
学位专业	化学工程
中文摘要	半导体氧化物气敏传感器由于实时响应、操作简便、成本低廉等优点在室内甲醛污染检测方面具有重要的应用前景。探索材料气敏性能的影响机制，制备高性能气敏材料，进而制备稳定工作的传感器器件对于实现甲醛浓度的原位、实时检测具有重要意义。本文以研究ZnO基气敏材料为基础，在考察评估其气敏性能的关键影响因素的前提下，以电泳沉积技术制备了初步的甲醛传感器。主要研究内容与结果包括：（1）针对静态气敏传感器性能测试装置的气体浓度配制不精确、与传感器接口不开放的缺点，设计了动态、开放式甲醛传感器气敏性能测试装置，为气敏材料的开发提供了准确、可靠的性能评价平台。基于此装置的开放式接口特性，针对广泛存在的空气湿度对传感器信号干扰的问题，通过调节材料的退火温度，得到了两种对甲醛和湿度气敏响应不同的ZnO基传感器。将这两种传感器组成阵列，通过补偿作用实现了甲醛传感过程对湿度的选择性，体现了动态、开放式气敏性能测试装置的优点；（2）采用沉淀－煅烧工艺制备了系列ZnO纳米颗粒，通过电镜观察、谱分析等表征测试手段系统考察了其气敏性能影响机制，得出初步结论：晶体缺陷是影响其气敏性能高低的主导因素。进而通过等离子体化学气相沉积法、水热法、锌粉氧化法制备了不同形貌的ZnO材料，研究了其晶体缺陷结构与甲醛气敏性能之间的关系，提出了基于晶体缺陷的材料机理模型：施主缺陷越多、受主缺陷越少则气敏性能越高，为高性能气敏材料的开发奠定了基础；（3）基于本文提出的材料机理模型，采用沉淀－煅烧法及水热法，分别使用Sn、Ga、Mn及Fe、Ti、Sn对ZnO进行了结构掺杂，以调节其晶体缺陷及甲醛气敏性能，得到了气敏性能较高的Sn掺杂ZnO材料。进而通过CdO掺混的方法提高材料表面的活性点位，得到了在较低温度下对甲醛具有较高响应的ZnO基气敏材料。（4）针对制备传感器器件的原位法成本高及异位法重复性差的问题，初步探索了以ZnO基材料的乙醇悬浮液为前驱体，快速、可控制备甲醛气敏传感器的电泳沉积技术。选用阳极氧化铝/铝（AAO/Al）的复合材料作为基底，克服了电泳沉积过程与气敏过程分别要求基底为导体与绝缘体的矛盾，丰富了气敏传感器的制备方法。
英文摘要	Due to its in-situ detection, easy manuplation and low-cost metal oxide semiconductor (MOS) gas sensors are promising in formaldehyde fast detection in indoor air. Exploring the sensing mechanism, preparing high response materials and fabricating stable working gas sensors are important in formaldehyde gas sensor. In this study, ZnO based materials are used for formaldehyde gas sensors and high response sensor is prepared guided by the modified material mechanism model proposed in this study, using electrophoretic deposition (EPD) method. The main research progresses are as follows: (1) Dealing with the disadvantages of static gas sensor test instrument, which are low-precise gas concentration and non-open interface, a dynamic and open interface one is substitutively developed insuring the precision and confidence of the experiment data. Based on the open interface feature, and tuning the gas sensing properties of ZnO based sensors to formaldehyde and humidity by annealing at different temperatures, a two-sensor array is then fabricated showing improved selectivity over humidity by make-up effect. (2) A series of ZnO nanoparticles are prepared by precipitateon-calcination method, and the key to high gas response is then studied by using systemic methods such as electron microscopy and spectra analysis, etc. The results show that defect structure is the dominant factor influencing the gas response, which is further verified by tuning the crystal defects and gas response in atmosphere annealing. In order to find more proofs, ZnO nanorods, nanoparticles and microparticles are prepared by plasma-enhaced chemical vapor deposition (CVD) method, hydrothermal method and zinc oxidation method respectively, whose gas sensing properties are studied from the aspect of crystal defects. Then a crystal defect based gas sensing material mechanism model is proposed: more donors and less acceptors favor gas response. (3) Based on this mechanism model, doping of ZnO by coprecipitation and hydrothermal methods is carried out in order to tailor its crystal structure and gas response, using Sn, Ga, Mn and Fe, Ti, Sn respectively. And high gas response Sn-doped ZnO is prepared. Further, mixed with CdO to enhance surface active cites, high response ZnO based gas sensing material working at low temperature is obtained. (4) Coping with the high cost of in-situ process and weak reproductivity of ex-situ process, electrophoretic deposition technology is investigated for formaldehyde gas sensor fabrication, using suspensions of ZnO based gas sensing material in ethanol. Facing the difficulty of EPD method in gas sensor fabrication, anodic aluminum oxide (AAO)/Al composite structure is chosen to serve both as the conductive electrode (Al layer) in EPD and the insulative substrate (AAO layer) in gas sensor, which enwidens the fabrication method for gas sensors.
语种	中文
公开日期	2013-09-17
页码	162
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1502]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	韩宁. 氧化锌基甲醛气敏材料的制备与气敏性能研究[D]. 中国科学院研究生院. 2010.

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