H2S sensing characteristics of La0.7Pb0.3Fe0.4Ni0.6O3 based nanocrystalline thick film gas sensor

In this paper, the structural and gas sensing properties of nanocrystalline La0.7Pb0.3Fe0.4Ni0.6O3 was prepared by a sol–gel citrate method. The structural characteristics of the material were studied by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD pattern shows a nanocrystalline solid solution of La0.7Pb0.3Fe0.4Ni0.6O3 with a perovskite phase. The gas sensing properties were studied for different reducing gases such as H2S, ethanol, CO and LPG. The La0.7Pb0.3Fe0.4Ni0.6O3 powder showed large response to H2S gas at an operating temperature 250 °C. Further improvement in response was achieved by the addition of 0.5 wt% Pd to La0.7Pb0.3Fe0.4Ni0.6O3. The sensor showed a good response to 150 ppm H2S gas at an operating temperature 200 °C.