Synthesis and characterization of uniform-sized cubic ytterbium scandium co-doped zirconium oxide (1Yb10ScSZ) nanoparticles by using basic amino acid as organic precursor

Cubic ytterbium scandium stabilized zirconium oxide (1Yb10ScSZ) nanoparticles with highly uniform sizes were synthesized using basic amino acid as organic precursor in aqueous medium. The 1Yb10ScSZ materials were prepared by precipitation (P-YbScSZ) and sol-gel (SG-YbScSZ) using l-arginine as the basic amino acid. l-Arginine can form complex gel with metal cation and increase the solution pH. The calcination temperatures were varied from 600 to 700 °C to study the effect of calcination temperature on particle size. The stable cubic phase ensured the high ionic conductivity of the zirconia-based electrolyte material for solid-oxide fuel cells (SOFC). The crystal structures of the nanoparticles obtained from the precipitation and sol-gel methods were cubic, but the nanoparticles obtained from the precipitation method calcined at 600 °C were more uniformly sized. However, the symmetrical cell with SG-YbScSZ powder sintered at 1550 °C/5 h showed a higher ionic conductivity value of 0.012 Ω cm2 at 800 °C and a lower activation energy than the cell using the P-YbScSZ powder. This finding demonstrated that the 1Yb10ScSZ electrolyte prepared by the sol-gel method had better properties, higher sinter ability, and ability to obtain sufficient density with better electrical property than that prepared by the precipitation method.