Effect of VOC on ozone detection using semiconducting sensor with SmFe1−xCoxO3 perovskite-type oxides

Fine particles of perovskite-type SmFe1−xCoxO3 oxides were synthesized by the thermal decomposition of the corresponding heteronuclear hexacyano complexes. The sensing characteristics of ozone, methylethylketone (MEK), ethanol and benzene were examined. These sensors responded to sub-ppm levels of ozone, and the sensitivity decreased with increasing working temperature. The response to 0.1 ppm ozone was ca. 1000 at 250 °C. The conductance of the sensors in ozone decreased due to the contamination of the same VOC levels. At around 200 °C, the cross sensitivity of some VOCs to ozone was quite depressed. The partial substitution of Co for Fe resulted in an increased conductance in air and a decrease in the sensitivity to ozone.