Preparation And Properties Of Cerium Oxide With Different Morphologies

Cerium dioxide, a kind of rare earth dioxides, is useful. How to combine its unique characteristics with nano-advantages for worthy application is the purpose of our study.We choose both traditional hydrothermal method to synthesize CeO2. The effect factors and formation mechanism were discussed. At the same time, the photocatalytic activity of CeO2nanomaterials in the degradation of methyl orange (C14H14N3NaO3S) was also investigated.Single-crystalline and uniform nanorods and nanocubes of cubic CeO2were selectively prepared by a hydrothermal method at temperatures in the range of100-200℃, using Ce(NO3)3as the cerium source. Systematic experiments were carried out to investigate the factors that affect the morphology of the samples. It was found that the hydrothermal temperature was the factor to determine the morphology of the CeO2and the size of the CeO2particles were controled by the NaOH concentrations. The formation mechanism of CeO2nanorods and nanocubes was interpreted by the increase of ceria monomers concentration. CeO2with rods-like morphology exhibited improved ability on the photocatalytic degradation of methyl orange (C14H14N3NaO3S) in aqueous solution under UV radiation compared with CeO2nanocubes. The higher photocatalytic activity of the CeO2nanorods result from the larger content of defects exist in the nanorods. It is thought that defects may act as the active centers of the catalyst, which could capture photo-induced electrons, whereas the recombination of photo-induced electrons and holes can be effectively inhibited.