Preparation and gas sensing characteristics of BiFeO 3 crystallites

Phase pure BiFeO3 crystallites with different grain sizes and morphologies were prepared via hydrothermal and coprecipitation methods. The gas sensing properties of the as-prepared BiFeO3 samples were investigated in different gaseous atmospheres containing ethanol, acetone, etc. The working temperature was set to 260 °C at which the sensitivity value reached a maximum. The results revealed that the sensor based on BiFeO3 powders presented p-type behavior which exhibited high sensitivity with short response time and effective gas selectivity. Moreover, it was found that the sensor response was greatly influenced by the BiFeO3 particle morphology, grain size and specific surface area. The gas sensing mechanism has been discussed.