Gas sensing with yolk-shell LaFeO3 microspheres prepared by facile hydrothermal synthesis

• Published in: Sensors and actuators. B, Chemical Chemical, 2018-04, Vol.258, p.1215-1222
• Main Authors: Wang, Boqun, Yu, Qi, Zhang, Sufang, Wang, Tianshuang, Sun, Peng, Chuai, Xiaohong, Lu, Geyu
• Format: Article
• Language: English
• Subjects: Acetone sensing; Facile hydrothermal method; Gas sensor; LaFeO3; Yolk-shell microspheres
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2017.12.018

•The yolk-shell LaFeO3 microspheres were synthesized by a convenient and effective hydrothermal route combined with annealing and etching process.•A possible evolution process of the yolk-shell structure was elucidated.•Comparison of gas sensing properties of LaFeO3 obtained at different hydrothermal stages revealed that yolk-shell LaFeO3 microspheres exhibited superior gas sensing properties because of their special structure.•The application in gas sensor of as-prepared LaFeO3 yolk-shell microspheres exhibited remarkable sensitivity and excellent selectivity toward acetone at 225°C. The mechanism of the enhanced acetone sensing was also discussed systematically. A facile hydrothermal route with the subsequent annealing and chemical etching process to the synthesis of yolk-shell LaFeO3 microspheres without any template is described. Transmission electron microscopy (TEM) images of the products obtained at different hydrothermal reaction time revealed the formation mechanism of yolk-shell LaFeO3 microspheres. Gas sensing devices were fabricated from the as-prepared samples, and their gas sensing properties were tested for response to various reducing gases. The sensor based on yolk-shell LaFeO3 microspheres exhibited high response and good selectivity toward acetone at 225°C, giving a response of 25.5–100ppm.