新型结构金属氧化物的制备及其气敏性能研究

发布时间：2018-06-15 08:15

本文选题：金属氧化物 + 气敏传感器　；参考：《西南交通大学》2017年硕士论文

【摘要】：当前环境污染问题日益突出,有毒有害气体监测成为环境治理的必要手段和重要保障,因此,先进气体传感器成为目前环境监测的研究热点。先进敏感材料与器件工艺是气体传感器研究的重点和核心,对新型高性能气敏传感器的研究具有重要的科学意义和应用价值。金属氧化物半导体材料因其灵敏度高、结构简单、价格低廉、易于集成等优点,在气敏传感器上表现出良好的应用价值。通过设计金属氧化物的微结构、调控组织与相成分、复合不同理化特性的材料,并研究其对气敏特性的影响机制,有望提高气敏传感器的灵敏性、选择性、稳定性,并降低气敏传感器的工作温度。本论文通过设计新型微结构金属氧化物MoO3、Fe_2O_3及其复合物,并探讨其在气敏传感器的应用研究。主要研究内容如下:(1)利用简单的热氧化法原位生长柔性大面积α-MoO3微米片规整阵列薄膜,这种薄膜沿着(110)晶面择优取向生长并表现出力学柔性。基于α-MoO3微米片阵列薄膜的敏感元件在目前实验条件下未检测到气敏特性,但是表现出良好的温度传感特性。(2)利用水热法无模板自组装技术制备仿生蕨类叶子状α-Fe_2O_3,其纯度高无任何杂质,微观结构与自然界中蕨类叶子高度相似,主干骨架与分支结构的角度大致为64°。基于蕨类叶子状α-Fe_2O_3的气敏元件对正丁醇表现出很好的敏感特性。在260℃下,其对100ppm正丁醇的灵敏度为8.26,对浓度为10、20、50和100ppm正丁醇的响应(恢复)时间分别为17.5 s(9 s),24 s(16 s),26 s(18 s)和34 s(21s)。而且,蕨类叶子状α-Fe_2O_3气敏元件表现出很好的稳定性和选择性。与颗粒状蕨类α-Fe_2O_3气敏元件相比,蕨类叶子状α-Fe_2O_3气敏元件对正丁醇的灵敏度高和响应(恢复)速率快。(3)通过对仿生蕨类叶子状α-Fe_2O_3的表面修饰,采用两步水热法成功制备出蕨类叶子状α-Fe_2O_3/SnO2异质结构材料。α-Fe_2O_3/SnO2复合材料具有较好的结晶性和高纯度,SnO2纳米颗粒沉积于α-Fe_2O_3表面,经化学复合后蕨类叶子状结构得到很好的保留。在200℃下,基于仿生蕨类叶子状α-Fe_2O_3/SnO2气敏传感器对10、20、50和100ppm正丁醇气体的灵敏度分别是5.41、9.29、15.01和22.73 s。与纯相α-Fe_2O_3气敏元件相比,α-Fe_2O_3/SnO2对100ppm正丁醇的灵敏度高出了2倍,气敏元件最佳工作温度由260℃降至200℃。
[Abstract]:The problem of environmental pollution is becoming more and more prominent, and the monitoring of toxic and harmful gases has become a necessary means and important guarantee for environmental control. Therefore, advanced gas sensors have become the focus of research on environmental monitoring. Advanced sensitive materials and device technology are the key and core of gas sensor research, and the research tools for new high performance gas sensors are studied. The metal oxide semiconductor material has the advantages of high sensitivity, simple structure, low price and easy integration. It has shown good application value on the gas sensor. By designing the micro structure of metal oxide, the materials which regulate the structure and phase composition and compound the different physical and chemical properties are studied and studied. The mechanism of its influence on gas sensitivity is expected to improve the sensitivity, selectivity and stability of the gas sensor and reduce the working temperature of gas sensors. This paper designs a new type of microstructural metal oxide MoO3, Fe_2O_3 and its complex, and discusses its application in the gas sensor. The main contents are as follows: (1) the use of simple The thermal oxidation method is in situ for the growth of a flexible large area alpha -MoO3 micron slice array film. This film grows along (110) crystal surface and shows mechanical flexibility. The sensitive elements based on the alpha -MoO3 micrometer array film have not detected the gas sensitivity under the present experimental conditions, but exhibit good temperature sensing properties. (2) use The bionic fern leaf like alpha -Fe_2O_3 was prepared by the hydrothermal method without template self-assembly. Its purity was high without any impurity, the microstructure was similar to the fern leaf in nature, and the angle of the backbone skeleton and the branch structure was approximately 64 degrees. The gas sensing element based on the fern leaf like alpha -Fe_2O_3 showed good sensitivity to n-butanol. At 260 degrees C The sensitivity of 100ppm n-butanol was 8.26, and the response time for 10,20,50 and 100ppm n-butanol was 17.5 s (9 s), 24 s (16 S), 26 S (18 s) and 34 s (21s). Moreover, fern leaf like alpha -Fe_2O_3 gas sensors showed good stability and selectivity. Compared with granular fern alpha gas sensors, ferns were compared. The sensitivity and response (recovery) rate of the leaf like alpha -Fe_2O_3 gas sensor are high. (3) the leaf like alpha -Fe_2O_3/SnO2 heterostructure material is successfully prepared by two step hydrothermal method through the surface modification of the bionic fern leaf like alpha -Fe_2O_3. The alpha -Fe_2O_3/SnO2 composite has good crystallinity and high purity, SnO2 The nano particles are deposited on the surface of alpha -Fe_2O_3, and the leaf like structure of ferns is well preserved. At 200, the sensitivity of the bionic fern leaf like alpha -Fe_2O_3/SnO2 gas sensor to 10,20,50 and 100ppm n-butanol gas is 5.41,9.29,15.01 and 22.73 S. compared with the pure phase alpha -Fe_2O_3 gas sensor, respectively, alpha -Fe_2O_3. The sensitivity of /SnO2 to 100ppm butanol is 2 times higher, and the best working temperature of gas sensor decreases from 260 to 200 degrees.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O659;TP212

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