CeO2 doped SnO2 sensor selective to ethanol in presence of CO, LPG and CH4

In the present study, the sensitivity of SnO2 and CeO2/SnO2 sensors to ethanol in the presence of CO, LPG and CH4 gases were examined. SnO2 and CeO2/SnO2 were prepared by a sol-gel method and sintered at 600 and 800 °C. As SnO2 is doped with 2.0 wt.% ceria, at 300 °C, the sensitivity to ethanol with respect to methane, LPG and CO is enhanced by factors of about 5.3, 48.2 and 5.2, respectively. As the temperature is increased to 350 °C, the ceria-doped SnO2 becomes more sensitive to CO and LPG. The results revealed that, for all gases, the sensitivity of the sensors sintered at 600 °C was higher than the ones sintered at 800 °C, however, the effect was much more pronounced with regards to ethanol. In addition, doping the SnO2 sensor with CeO2 reduces the long recovery time observed for pure SnO2 sensor in presence of ethanol.