Co-Doped LaFeO3 Gas Sensor for Fast Low-Power Acetone Detection

Co-doped LaFe 1− x Co x O 3 ( x = 0, 0.1, 0.2, 0.4, 0.6, 0.9) nanomaterial films were prepared via a citric acidassisted sol–gel method and characterized by various techniques. Compared with pure LaFeO 3 , the optimum operating temperature of the LaFe 0.9 Co 0.1 O 3 gas sensor dropped to 110 °C from 140 °C. The response value to 100 ppm acetone was 35.89, with a fast response–recovery time of 14/9 s. The enhanced gas sensitivity may be attributed to the higher number of surface oxygen vacancies and larger specific surface area of LaFe 0.9 Co 0.1 O 3 . Doping with Co ions improved the moisture resistance of the LaFeO 3 sensor at 18%–54% relative humidity. Appropriate doping of Co 3+ into LaFeO 3 nanofibers is a promising method for designing and fabricating an acetone sensor with high gas-sensing performance.