Sulfur Doped Ceria Mesoporous Nanomaterial: Solid-State Synthesis, Characterization and Photocatalytic Property of Methyl Orange

摘要

To investigate the photocatalytic performance of rare-earth metal oxide modified with nonmetal, the sulfur doped ceria (S-CeO2) mesoporous nanomaterials with high visible light-driven activity was successfully prepared by a simple solid state reaction method at low temperature using sodium benzene sulfonate as a template. The samples were characterized by X-ray powder diffraction, high resolution transmission electron microscopy/energydispersive X-ray spectroscopy, UV-vis absorption spectra, infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and N2 adsorption-desorption. The doping mechanism and photo-catalytic degradation of methyl orange under visible light irradiation were discussed. The results show that the S-CeO2-SBS has cubic fluorite structure with high BET surface area of 104.3 m(2)/g and the egg-shaped morphology of mesoporous architecture. It is composed of ca. 13 nm nanoparticles by self-assembly and accumulation. The S atoms are successfully incorporated into the (111) and (200) crystal surface of CeO2 lattice as a S(IV) and S(VI) with the assistance of SBS template, respectively, and caused the generation of oxygen vacancies, structure defects and Ce(III) ions. As compared to pure CeO2, its ultraviolet visible diffuse reflectance absorption band red shifts to 500 nm with the enhancement of light absorption intensity. Under visible-light irradiation at room temperature within 80 min, the photocatalytic oxidation activity of methyl orange follows an order of S-CeO2-SBS (98.6%) S-CeO2 (68.4%) CeO2-SBS (42.2%) CeO2 (29.3%).