Preparation of CeO2 Nano Rods Through a Sonication‐Assisted Precipitation

Abstract

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).