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

A set of multicomponent perovskite oxide nanoparticles based on La۱-xSrxCo۱-yFeyO۳-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(NO۳)۳.۶H۲O], strontium nitrate [Sr(NO۳)۲], cobalt nitrate hexahydrate [Co(NO۳)۲.۶H۲O], ferric nitrate nonahydrate [Fe(NO۳)۳.۹H۲O] [as basic materials] and sodium hydroxide [as precipitator material] and PVA [as surfactant]. Throughout the experiment, pH was maintained as pH > ۹ 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 (۱:۹ volume %) to remove any unwanted impurities present along with the precipitate. The purified precipitate was dried at ۵۰ – ۱۰۰oC and heat treated at ۳۰۰oC, ۴۵۰oC, ۶۰۰oC and ۷۵۰oC for ۲ 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.

Keywords:

Chemical precipitation , Multicomponent Perovskite Oxide nanoparticles , Cathode materials , SOFC