Synthesis and characterization of cerium dioxide fibers

Fibrous ceria, which is an important ionic material used for solid electrolyte, has been synthesized by a new chemical co-precipitation/ripening method. Aqueous nitrate solutions containing NaOH/C6H8O7 are used to grow various Gd- and Sm-doped CeO2 fibers. The growth mechanism and microstructural properties of the fibers are investigated. Other than fibers, three precipitates either in the forms of spherical colloids, flaky, or stick-in-bundle morphologies have also been obtained by similar precursor solutions. The morphologies of those precipitates are greatly affected by the concentration ratio of the Ce(NO3)3/NaOH/C6H8O7. The fibrous feature is retained by calcination at a temperature up to 1200 °C in 1 h. Reaction kinetics and the chemical composition changes of the fibers are reported.