Conductivity Extent in Hydrothermally Synthesized Nanocrystalline Ceria

Abstract

The synthesis of cerium oxide (CeO₂) nanoparticles through composite mediated hydrothermal approach is reported. A composite of sodium hydroxide and potassium hydroxide was used as precursor with cerium nitrate as the raw material. With the help of X-ray diffraction (XRD), we observed that the crystal structure of prepared ceria nanoparticles is cubic. Scanning electron microscopy (SEM) has been utilized to study the surface morphology of the material. Conductivity of synthesized cerium oxide was measured by standard two probes method. Cerium oxide is nonconductive at room temperature, but when we increase the temperature, it becomes conductive. It is observed that ionic conductivity depends on nature of nanoparticles and temperature. The oxygen ions conductivity was 2.32 ×10⁻⁸ S cm⁻¹ at 300 ± 5 ^∘C. In the region of 300 ± 5 to 400 ± 5 ^∘C, the conductivity increases slightly. Above 400 ± 5 ^∘C, it increases rapidly and gave a maximum value of 1.01 × 10 ⁻⁷ S cm⁻¹ at 700 ± 5 ^∘C. Also, the effect of applied frequency on the conductivity, dielectric constant, and dissipation factor was observed as a function of temperature. The studied material is a strong potential candidate for electrolyte material in intermediate temperature solid oxide fuel cells (ITSOFC).