Novel hydrothermal synthesis of hexagonal prism-like CeO sub(2) nanotubes and their optical properties

The hexagonal prism-like CeO sub(2) nanotubes have been successfully synthesized via a facile hydrothermal method using Ce(OH)CO sub(3) hierarchical structures as precursors. X-ray diffraction inferred that the synthesized CeO sub(2) nanotubes exhibited a fluorite cubic structure. The scanning electron microscope and transmission electron microscope revealed that the CeO sub(2) samples have a hexagonal tube-like structure, while bundle-like hierarchical structure was obtained in original solution. X-ray photoelectron spectroscopy and the Raman spectroscopy reflected the existence of the oxygen vacancies and Ce super(3+) ions in the hexagonal CeO sub(2) nanotubes. There is a red-shifting in the band gap of the material compared to bulk one, which is mainly attributed to the influences of the Ce super(3+) ions, oxygen vacancies and the novel morphology.