Ethanol sensing characteristics of BaTiO3/LaFeO3 nanocomposite

BaTiO3/LaFeO3 nanocomposite with BaTiO3 and LaFeO3 nanoparticles in the mole ratio of 1:2 was prepared by a citric sol-gel method and used as sensing materials to fabricate nanoparticle-based sensors. TEM, BET and XPS results suggested that the capability of absorbing oxygen species from air played the more important role than the grain size or specific surface area in the determination of gas sensing performance for nanoparticles. BaTiO3/LaFeO3 sensor showed improved gas response towards ethanol with respect to the LaFeO3 sensor at the expense of deteriorated dynamic response. Owing to the higher content of adsorbed oxygen species and ratio of Fe4+/Fe on the surface of the sensing material, better and stable sensing performance to ethanol was achieved by the BaTiO3/LaFeO3 sensor at the prime working temperature of 128 °C, with a high gas response (102.7) to 100 ppm ethanol.