Application of a modified ultrasonic aerosol device to the synthesis of SnO2 and Pt/SnO2 for gas sensors

SnO2 and Pt/SnO2 powders were synthesized with a modified ultrasonic aerosol pyrolysis device. The advantages of this new method were tested by comparison of pure SnO2 powders synthesized by conventional and modified aerosol methods. Then, the synthesis of SnO2 with Pt was carried out by this new method. The droplet evaporation and pyrolysis processes induce the formation of materials with a fine microstructure that exhibit, after annealing, a high sensitivity to ethanol or CO in air. In the Pt/SnO2 powders, platinum aggregates dispersed onto the SnO2 grains improve the sensitivity of SnO2 powders when the sample is annealed at 700 C. Therefore, a Pt/SnO2 sample submitted to such thermal treatment is a good candidate for CO and C2H5OH detection due to its sensitivity to both gases. 18 refs.