Low‐Temperature Synthesis and Gas Sensitivity of Perovskite‐Type LaCoO₃ Nanoparticles

LaCoO 3 nanoparticles with perovskite‐type structure were prepared by a microwave‐assisted colloidal method. Lanthanum nitrate, cobalt nitrate, and ethylenediamine were used as precursors and ethyl alcohol as solvent. The thermal decomposition of the precursors leads to the formation of LaCoO 3 from a temperature of 500°C. The structural, morphological, and compositional properties of LaCoO 3 nanoparticles were studied in this work by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). Pellets were manufactured in order to test the gas sensing properties of LaCoO 3 powders in carbon monoxide (CO) and propane (C 3 H 8 ) atmospheres. Agglomerates of nanoparticles with high connectivity, forming a porous structure, were observed from SEM and TEM analysis. LaCoO 3 pellets presented a high sensitivity in both CO and C 3 H 8 at different concentrations and operating temperatures. As was expected, sensitivity increased with the gas concentration and operation temperature increase.