LaCoO3-based sensors with high sensitivity to carbon monoxide

LaCoO3 nanoparticles with particle sizes of similar to 82 nm were prepared by co-precipitation, and mesoporous LaCoO3 thick films with a thickness of similar to 7 mu m were fabricated by screen printing the nanoparticles on Al2O3 substrates. The CO sensing properties of the LaCoO3 thick films were characterized in the temperature range of 100 to 550 degrees C. Under 5000 ppm CO at 500 degrees C, the thick film sensor achieved a high sensing response of similar to 279.86, with response and recovery periods of 181 and 311 s, respectively. Under 25 ppm CO at 500 degrees C, a reasonable response of 1.04 was also achieved. Moreover, the sensor demonstrated reliable dynamic response-and-recovery at a temperature as low as 100 degrees C, therefore, LaCoO3 is very promising for CO sensing at low temperatures. The high response to CO could be ascribed to the high content of O-2(2-)/O- species in LaCoO3.