| Summary: | 碩士 === 逢甲大學 === 材料科學與工程學系 === 105 === In this study, uncoated CeO2 and 0.5-5.0 mol% Fe-coated CeO2 (cerium oxide) nanocrystalline particles were respectively prepared from two precursors of cerium nitrate and cerium acetate by spray pyrolysis and photoreduction methods. The composite samples were characterized by XRD, FESEM, UV-VIS, and PL.The photocatalytic activity was evaluated by the degradation of methyl orange in aqueous solution under visible light irradiation. Compared with the uncoated CeO2, a small amount of Fe coating can effectively inhibit the recombination of electron-hole pairs to increase the photocatalytic activity. The light absorption edge of the Fe-coated samples can also be extended from the ultraviolet region to the visible light region. At the same time,iron ions can act as electron acceptor and hole donor, facilitating longer lived charge carrier separation in the Fe-coated CeO2.The photocatalytic efficiency of CeO2 powders was evaluated by the experiments of photodegradation of methyl orange under visible light irradiation. Highest photocatalytic activity of CeO2 was obtained by coating with 0.5 mol% iron. A comparison with the samples derived from cerium acetate, the photodegradation efficiency of CeO2 derived from cerium nitrate can be significantly improved from 0% to ca. 45% with the incorporation of 0.5 at% iron coating. Whereas the highest photodegradation efficiency of CeO2 derived from cerium acetate is ca. 17%.
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