Resistive oxygen gas sensors based on CeO2 fine powder prepared using mist pyrolysis

Mist pyrolysis was used to prepare cerium oxide (CeO2) fine powder. The average particle size was 200 nm. Using the powder, resistive oxygen gas sensors based on porous thick films were fabricated by screen printing and firing at 1473 K for 2 h in air. The microstructure of the fired thick film showed the neck growth and the random network structure of cerium oxide powder with no significant grain growth. The response time (t90) for oxygen gas sensors having an average particle size of 200 nm was one-tenth as long as that for those with 2000 nm particles after a sudden change of oxygen partial pressure, P(O2), from 105 to 103 Pa in the temperature range of 873–973 K.