Yttrium-doped hedgehog-like ceria with a high concentration of oxygen vacancies was successfully prepared by a traditional hydrothermal process. Crystal phase composition, morphology, and size of as-fabricated products were found to be greatly dependent on the mole ratio of original materials and reaction temperature. The morphology and size of the as-prepared samples were characterized by FE-SEM, HR-TEM and HADDF-STEM. Structure information was obtained by XRD and Raman analyses. Absorption band and band gap energy, which are responsible for the observed photocatalytic behavior, were investigated by UV-vis diffuse reflectance. In addition, the optimum experimental conditions for target products were determined. The as-prepared doped three dimensional (3D) hierarchical structure samples showed higher photocatalytic activity than that of one dimensional (1D) octahedral and nanorod morphology ceria as evaluated by measuring CO2 liberation form the photocatalytic decomposition of acetaldehyde. (C) 2014 Elsevier B.V. All rights reserved.