Preparation of CeO2 Nano Rods Through a Sonication‐Assisted Precipitation

A CeO₂ nanopowder has been synthesized using sonication‐assisted precipitation. The use of ultrasonics during precipitation showed potential morphology control during synthesis. The sonication‐assisted precipitation with highly aqueous base (20 M NaOH) successfully induced the formation of a one‐dimensional nanostructure of CeO₂ rods with a homogeneous shape and size (TEM: 24 nm diameter and 129 nm long). A conventional precipitation under the same conditions provided the CeO₂ in nonuniform sizes and shapes. Heat treatment (1100°C for 4 h) was required for CeO₂ formation when (NH₄)₂C₂O₄ was used instead of NaOH. The concentration of the precipitation agent (15–20 M) strongly affected the size and shape of the product. Importantly, according to the temperature‐programmed reduction/oxidation study, the CeO₂ prepared using the sonication‐assisted route showed a relatively higher level of reversible oxygen storage capacity (2384 μmol/g), compared with the CeO₂ prepared by conventional route (1748 μmol/g).