CO₂ sensing properties and mechanism of nanocrystalline LaFeO₃ sensor

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• 作者：Xiaofeng Wang ; Hongwei Qin ; Lihui Sun ; Jifan Hu
• 关键词：Gas sensors ; CO2 ; Perovskite ; Sensing mechanism
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2013
• 出版时间：November, 2013
• 年：2013
• 卷：188
• 期：Complete
• 页码：965-971
• 全文大小：2180 K

文摘

LaFeO₃ nanocrystalline powders prepared by sol-gel method with annealing at 800 ¡ãC for 2 h can exhibit considerable sensing response to CO₂ gas. The resistance of the LaFeO₃ sensor increases with increasing concentration of CO₂. At 300 ¡ãC, the response of the sensor to 2000 ppm CO₂ is 2.19, and its response and recovery times are about 4 and 8 min, respectively. The possible CO₂ sensing mechanisms for LaFeO₃ sensor are investigated with first principles calculations. Calculated results demonstrate that CO₂ could release electrons to the surface of LaFeO₃ (0 1 0) pre-adsorbed with high concentration of oxygen, which is consistent with the experimental observation.