Structural, morphological and excellent gas sensing properties of La1–2xBaxBixFeO3 (0.00 ≤ x ≤ 0.20) nanoparticles

Abstract In the present paper, the La1–2xBaxBixFeO3 (x = 0.00, 0.05, 0.10, 0.15 and 0.20) nanosized perovskite materials have been successfully prepared by the auto-combustion route using the glycine as fuel. The structural, morphological, and gas sensing properties of these samples have been investigated. The Rietveld refinement has revealed a single orthorhombic phase (Pnma space group) for the compounds with x ≤ 0.10, while the samples with x = 0.10 and 0.20 have been found to contain a minor amount of two secondary phases. We have confirmed that the La0.8Ba0.1Bi0.1FeO3 (x = 0.10) compound possesses the smallest average particle size (34.58 nm) with the purely orthorhombic structure and exhibits a high surface roughness, as determined by atomic force microscopy measurements. Importantly, the gas sensing tests have been carried out for all prepared compounds with different ethanol and H2S gas concentrations (from 5 to 100 ppm). The La0.8Ba0.1Bi0.1FeO3 (x = 0.10) compound has been proven to exhibit excellent performance in ethanol and H2S gas response even for very low concentrations (5 ppm) with an optimum operating temperature of 180 and 200 °C, respectively. Furthermore, the response and recovery times analyzed for both these gases were found to be very short (between 5 and 10 s).