Nanocrystalline Gd1–xCaxFeO3 sensors for detection of methanol gas

• Published in: Journal of rare earths Vol. 35; no. 7; pp. 690 - 696
• Main Author: 王小风 马威 孙凯铭 胡季帆 秦宏伟
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2017
• Subjects: electrical properties; gas sensor; methanol; perovskite; rare earths; gas sensor; methanol; perovskite; electrical properties; rare earths
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(17)60965-7

The sol-gel method was used to prepare the nanocrystalline Gd_（1–x）Ca_xFeO_3 （x=0–0.4） powders. The XRD results showed that all the Gd_（1–x）Ca_xFeO_3 （x=0–0.4） compounds crystallized as perovskite phase with orthorhombic structure. The doping of Ca in GdFeO_3 not only reduced the resistance, but also enhanced the response to methanol. The Gd_（0.9）Ca_（0.1）FeO_3 showed the best response to methanol among Gd_（1–x）Ca_xFeO_3 sensors. Besides, it showed good selectivity to methanol among methanol, ethanol, CO and formaldehyde gases. The responses at 260 oC for Gd_（0.9）Ca_（0.1）FeO_3-based sensor to 600 ppm methanol, ethanol and CO gases were 117.7, 72.7 and 31.9, respectively. Even at quite low gas concentrations, Gd_（0.9）Ca_（0.1）FeO_3-based sensor had an obvious response. At 260 °C, the response of 1.54 was obtained to be 45 ppm methanol. The experimental results showed that nanocrystalline Gd_（0.9）Ca_（0.1）FeO_3 based sensor can be used to detect methanol gas.