A fast response & recovery acetone gas sensor based on BiFeO_3 nanomaterials with high sensitivity and low detection limit

摘要

AbstractIn present work, BiFeO3was synthesized at different temperatures (450, 500, 550 °C) by tartaric acid sol–gel method. XRD, SEM and TEM were used to characterize microstructure and morphology of as-prepared BiFeO3. All results indicate that as-prepared BiFeO3is the nanocrystal with single rhombohedrally distorted perovskite structure with the space group R3c and has irregular shapes and the average grain sizes between 50 and 120 nm. BiFeO3nanomaterials have a low working temperature of 240 °C and high acetone gas response. Especially for BiFeO3grown at 500 °C, the sensitivity to 50 ppm acetone is about as high as 30 at 240 °C. The response and recovery time of BiFeO3sensors is respectively about 5 and 18 s. Moreover, BiFeO3sensors have a low detection limit and the logarithmic curves of the sensitivity and concentration of BiFeO3sensors satisfy the linear relationship in the low detection range. These results demonstrate that BiFeO3can be used as an ideal candidate to fabricate high response acetone sensor. Gas sensing mechanism of BiFeO3is also discussed on the basis of adsorption and desorption of reducing acetone gas and the reaction with oxygen species on the surface of BiFeO3nanomaterials. This work can give rise to an interesting choice for researching excellent gas sensing properties of other nonstoichiometric oxides.