【作者】 王欢；

【导师】 余萍；

【作者基本信息】 四川大学 ， 材料物理与化学， 2006， 硕士

【摘要】 随着工业的发展，工业生产和日常生活中使用的化学原料和在生产过程中产生的气体种类和数量越来越多。这些气体中，有毒气体不仅污染环境，而且严重威胁着人类的健康和安全，尤其是芳香族化合物中的芳香烃即苯类化合物（苯、甲苯、二甲苯）和醛类气体对人体健康的损害十分严重。因此对这几类VOCs进行有效便捷的监测，引起了人们极大的关注。 本论文采用固相合成的方法制备了在TiO₂中分别混合不同原子百分比的Al₂O₃、SnO₂、In₂O₃和Cr₂O₃的敏感材料，并采用传统的陶瓷型气敏传感器的制备工艺制备了气敏元件。对上述气敏材料及传感器对苯、甲醛等气体的气敏特性进行了测试。研究了材料的化学组分对气敏特性的影响，加热功率对材料气敏特性的影响及气敏传感器的响应—恢复时间。结果表明：在TiO₂中，分别混合SnO₂、In₂O₃或Cr₂O₃的传感器对苯都有响应，其中以混合SnO₂的传感器对苯的灵敏度最好；混合In₂O₃或Cr₂O₃的传感器对丙酮气体有较好响应；混合SnO₂或Cr₂O₃的传感器元件对甲醛气体都表现出较好的响应，且其中以混合Cr₂O₃的元件更为灵敏。 另外，我们还分别采用固相合成和溶胶—凝胶工艺制备了不同TiO₂／Cr₂O₃配比的一系列TiO₂／Cr₂O₃敏感材料，比较研究了不同材料制备工艺对气敏材料的气敏特性的影响。气敏特性研究结果表明：用固相合成法制备的Cr含量为48.50at％的TiO₂／Cr₂O₃敏感元件对苯和甲醛都有最好的灵敏性和选择性，可有效检测21.5ppm苯和26.1ppm甲醛气体。其最佳工作（加热）电压都为5.5V。对苯和甲醛的平均响应时间分别是20s和2min，恢复时间较长，还需改进。更多还原

【Abstract】 In recent years, the demand of sensors for safety control and environmental monitoring has been expanded enormously. Especially, more and more people pay much attention on the detection of volatile organic compounds （VOCs） such as formaldehyde, pyridine, trichloroethylene, benzene, toluene, ethylene, etc.. The volatile organic compounds （VOCs） are much harmful to living things. For example, the aromatic hydrocarbons such as benzene, has been found to be responsible for the leucocythemia and lung cancer. And they are frequently encountered in every day life. For example, they exis in unleaded gasoline, paint, etc. So, it is necessary to develop a cheap and portable technique to detect or measure these kinds of substances, in the air.In this thesis, the VOCs gas sensing materials are prepared by solid state reaction method and sol-gel method respectively using TiO₂, Al₂O₃, SnO₂,In₂O₃ and Cr₂O₃ powders as raw materials. The ceramics gas sensors are made from above sensing materials prepared by means of traditional ceramics gas sensor processing. And the gas properties of these sensors are measured. The optimal composition of the sensing materials and the optimal sensor processing are obstained.The results demonstrated that the ceramic sensors made from TiO₂ mixed SnO₂, In₂O₃ or Cr₂O₃ powders respectively are all sensitive to benzene, and the sensors made from TiO₂ mixed with SnO₂ powders have the best sensitivity to benzene. The ceramic sensors made from TiO₂ mixed with In₂O₃, or Cr₂O₃ powders respectively show good response to acetone. The ceramic sensors made from TiO₂ mixed SnO₂ or Cr₂O₃ sensors show good sensitivity to formaldehyde and the Cr₂O₃ -mixed sensors更多还原