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

Co-doped LaFe1−xCoxO3 (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 LaFeO3, the optimum operating temperature of the LaFe0.9Co0.1O3 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 LaFe0.9Co0.1O3. Doping with Co ions improved the moisture resistance of the LaFeO3 sensor at 18%–54% relative humidity. Appropriate doping of Co3+ into LaFeO3 nanofibers is a promising method for designing and fabricating an acetone sensor with high gas-sensing performance.