Synthesis, characterization and sensitivity tests of perovskite-type LaFeO3 nanoparticles in CO and propane atmospheres

Abstract

Nanoparticles of perovskite-type LaFeO3 were synthesized by a simple process using stoichiometric lanthanum and iron nitrates, ethylenediamine, and distilled water as a solvent. Microwave radiation, with a power of ~350 W, was applied for solvent evaporation. The obtained precursor powders were calcined at 200, 400, 500, 600 and 700 °C in static air, and analyzed by X-ray diffraction and cyclic voltammetry. The samples showed catalytic activity and high physical and chemical stability. The calcined powders at 700 °C were analyzed through scanning and transmission electron microscopy; agglomerated nanoparticles, forming a porous structure, were observed with an average size of 28 nm. Their magnetic properties correspond to magnetization up to 0.83 emu/g and coercivity of 182 Oe. Pellets from these powders were prepared to measure the sensitivity to CO and propane gases, obtaining high performance at different gas concentrations and operation temperatures.