Synthesis of nickel coated gadolinia doped ceria nanopowders by microwave radiation

Abstract

Nickel coated gadolinium doped ceria (GDC) powders were synthesized by microwave radiation and combustion. For the synthesis, precipitates of gadolinium cerium oxycarbonate hydrate (GdxCe2-xO(CO3)(2) center dot H2O) were formed by a microwave-radiated reaction between cerium nitrate (Ce(NO3)(3) center dot 6H(2)O), gadolinium nitrate (Cd(NO3)(3) center dot 6H(2)O) and urea (CO(NH2)(2)), then nickel coatings on the gadolinium cerium oxycarbonate hydrate were performed by a further microwave reaction between nickel chloride and urea. The shape and size of the gadolinium cerium oxycarbonate hydrate particles were critically dependent on aging time during the microwave radiation. Irregular particles were transformed to rod-shape particles which were well-crystallized by increasing the aging time to 40 minutes at 70-80 degrees C because of the gradual decomposition of urea during the microwave radiation. Small nickel precursor particles were homogeneously coated on the gadolinium cerium oxycarbonate hydrate particles with a rod shape with aid of microwave radiation at 80 degrees C for 40 minutes. As a result, nickel coated GDC nanopowders were successfully produced by the microwave radiation synthesis and further microwave combustion at 450 degrees C for 20 minutes.