Chemical precipitation and characterization of multicomponent Perovskite Oxide nanoparticles – possible cathode materials for low temperature solid Oxide fuel cell

摘要

A set of multicomponent perovskite oxide nanoparticles based on La1-xSrxCo1-yFeyO3-δ(LSCF) were prepared by a simple chemical precipitation method for application in low temperature solid oxide fuel cells (LT-SOFC) as cathode materials.? The precursor materials used in this synthesis were lanthanum nitrate hexahydrate [La(NO3)3.6H2O], strontium nitrate [Sr(NO3)2], cobalt nitrate hexahydrate [Co(NO3)2.6H2O], ferric nitrate nonahydrate [Fe(NO3)3.9H2O] [as basic materials] and sodium hydroxide [as precipitator material] and PVA [as surfactant]. Throughout the experiment, pH was maintained as pH 9 by the addition of alkali (NaOH). A mixture of metal hydroxides (brown coloured) was formed when the aqueous mixture of basic materials mixed with the aqueous precipitant (NaOH) solution in proper stoichiometric compositions. The resultant hydroxide mixture was washed with ethanol and water mixture (1:9 volume %) to remove any unwanted impurities present along with the precipitate. The purified precipitate was dried at 50 – 100oC and heat treated at 300oC, 450oC, 600oC and 750oC for 2 hours each to get phase pure composite oxide powder. The resultant powder was characterized with TGA / DTA, XRD, FT-IR, Particle Size analysis and SEM. From the results, it was found that the chemical precipitation can be used effectively to prepare phase pure multicomponent perovskite oxides for application in SOFCs.