The effects of annealing temperature on the CO-sensing property of perovskite La0.8Pb0.2Fe0.8Cu0.2O3 nanoparticles

In this paper, perovskite La0.8Pb0.2Fe0.8Cu0.2O3 nanoparticles were synthesized by a sol–gel method using citric acid as complexing reagent. The thermal stability, grain size and structural properties of La0.8Pb0.2Fe0.8Cu0.2O3 calcined at different temperatures were studied using thermogravimetric analysis and differential scanning calorimeter analysis (TG–DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The results show that the annealing temperature affects only the grain size of the synthesized La0.8Pb0.2Fe0.8Cu0.2O3 nanoparticles but does not change its perovskite structure, confirming the thermal stability of the synthesized material. The electrical and CO gas response properties of La0.8Pb0.2Fe0.8Cu0.2O3-based sensors were investigated by the gas sensor characterization system. Results demonstrate La0.8Pb0.2Fe0.8Cu0.2O3 sample calcined at 800 °C exhibits higher response and good selectivity to CO. In addition, the structural and CO-sensing properties of La0.8Pb0.2Fe0.8M0.2O3 (M = Co, Ni and Cu) were discussed. As a result, Co-doping sample shows the highest response and the lowest operating temperature.