A sensitive material is prepared with metal oxide semiconductor SnO2 and 40% active La2O3,exhibits the sensitivity to CO2. The mixture can measure the volume fraction of CO2(0 ~5000) x10-6.The experimental results show that the sensitivity and the stability of the SnO2-La2O3 sensitive material have been enhanced by the addition of appropriate amount of metal oxides as CeO2, Ag2O and SiO2. The mixture with the addition has a higher sensibility to CO2. On the basis of the experimental result of this series of materials, the mechanism of sensitivity to CO2 is analyzed and discussed. The CO2 gas sensor based on these sensitive materials has many advantages such as simple structure,easy preparation,convenient operation,low price. It can be used for environmental monitoring of air and agricultural greenhouses.%以半导体氧化物SnO2为基体材料加入40％的活性La2O3材料,制备出了对CO2具有敏感性的气体敏感材料,其检测体积分数范围为(0～5000) ×10-6.实验结果表明:在SnO2-La2O3敏感材料的基础上掺杂适量CeO2,Ag2O,SiO2等氧化物,不仅提高了其对CO2气体的灵敏度,而且可以提高其稳定性,从而大大改善了其对CO2的敏感特性.在实验结果的基础上,分析并讨论上该系列材料对CO2气体的敏感机制.基于这种敏感材料的CO2气体传感器具有结构简单、制备简便、使用方便和价格低廉等优点,可用于空气环境监控和农用大棚等场合.
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