Synthesis and photocatalytic performance of yttrium-doped CeO2 with a hollow sphere structure

We report a facile and novel approach to prepare yttrium-doped CeO2 with a hollow sphere hierarchical structure by a simple hydrothermal method with cerium nitrate hexahydrate and yttrium nitrate hexahydrate as original materials and polystyrene microsphere as a soft-template. Through systematic experiments, the effects of experimental parameters such as doping and morphology on photocatalytic characteristics of the ceria were examined in detail. The morphology and element distribution of the as prepared samples were characterized by field emission scanning electron microscopy and high-resolution transmission electron microscopy. Structure information with Rietveld refined data were obtained by using an X-ray diffractometer. Intrinsic oxygen vacancies and extrinsic oxygen vacancies caused by doping were analyzed from Raman spectra. Analyses of elements and chemical valence analysis were carried out by X-ray photoelectron spectroscopy, and changes in reactive oxygen species were determined by calculation. Based on structural information, element valence states, and the results of photocatalytic decomposition of acetaldehyde, we can draw the conclusion that Y-doped CeO2 with a hollow sphere hierarchical structure has high photocatalytic activity, attributed to more oxygen vacancies and surface active oxygen species. Yttrium doped ceria with hollow sphere structure has a maximum rate constant of 0.0267 h(-1) and an oxidation quantum efficiency of 0.3610%, which are about 2 times as high as that of pure CeO2 with octahedral structure. (C) 2016 Elsevier B.V. All rights reserved.