标题：CO2 gas sensors based on Yb1-xCaxFeO3 nanocrystalline powders
作者：Zhang Panpan; Qin Hongwei; Zhang Heng; Lu Wei; Hu Jifan
作者机构：[ZHANG, P] School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China;[ QIN, H] School of Physics, State Key Laboratory f 更多
通讯作者地址：[Lu, W]Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China;[Hu, JF]Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Pe 更多
关键词：gas sensor;CO2;perovskite;rare earths
摘要：In this study, the Yb1-xCaxFeO3 (0≤x≤0.3) nanocrystalline powders were prepared by sol-gel method. We used the method of quantitative analysis to research the gas-sensitive properties for Yb1-xCaxFeO3 to CO2. Also, we investigated theeffects of various factors on gas sensing properties by simple variable method. The doping of Ca could not only decrease the resistance of YbFeO3, but also enhance its sensitivity to CO2. When the Ca contentx=0.2, Yb1-xCaxFeO3 showed the best response to CO2. The responseRg/Ra to 5000 ppm CO2 for Yb0.8Ca0.2FeO3 at its optimal temperature of 260 °C with the room temperature humidity of 28%RH was 1.85. The response and recovery time decreased with an increase of the operating temperature for Yb0.8Ca0.2FeO3 sensor to 5000 ppm CO2. Furthermore, with an increase of CO2 concentration from 1000 to 50000 ppm, the response time of Yb0.8Ca0.2FeO3 became shorter, and meanwhile the recovery time was longer. CO2-sensing response for Yb0.8Ca0.2FeO3 increased with the increase of relative humid-ity. The response for Yb0.8Ca0.2FeO3 in the background of air (with the room temperature humidity of 39%RH) at 260 °C could reach 2.012 to 5000 ppm CO2, which was larger than the corresponding value (1.16) in dry air.