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分别利用P123、正硅酸乙酯(TEOS)为模板剂和硅源,在酸性条件下合成了介孔SBA-15材料。利用SBA-15为硬模板剂,La(NO3)3/Pr(NO3)3和Ce(NO3)3为前驱体,通过煅烧方法制备了La-Pr-O/Ce-Pr-O和SiO2混合物。使用2 mol·L-1的NaOH溶液对混合物中的氧化硅进行溶解,获得La-Pr-O/Ce-Pr-O复合氧化物。采用X射线衍射仪、Raman光谱仪、N2吸-脱附技术、透射电镜及紫外-可见光谱仪对La-Pr-O/CePr-O复合氧化物进行了表征。Raman和X射线衍射结果表明产物具有与CaF2相似的萤石结构;N2吸-脱附结果证明产物为介孔结构。紫外-可见光谱表明,在Ce-Pr-O固溶体中,随着Pr含量提高,产物对光(特别是可见光)的吸收强度急剧增加;而在Ce-La-O固溶体中,随着La含量提高,产物对可见光的吸收强度基本保持不变。
Mesoporous SBA-15 was synthesized under acidic conditions using P123, TEOS as template and silicon source respectively. The La-Pr-O / Ce-Pr-O and SiO2 mixtures were prepared by calcination using SBA-15 as hard template, La (NO3) 3 / Pr (NO3) 3 and Ce (NO3) 3 as precursors. The silica in the mixture was dissolved using 2 mol·L-1 NaOH solution to obtain La-Pr-O / Ce-Pr-O composite oxide. The La-Pr-O / CePr-O composite oxides were characterized by X-ray diffraction, Raman spectroscopy, N2 adsorption-desorption, transmission electron microscopy and UV-Vis spectroscopy. Raman and X-ray diffraction results show that the product has a similar fluorite structure to CaF2; the N2 adsorption-desorption result proves that the product is a mesoporous structure. UV-Vis spectra showed that the absorption intensity of light (especially visible light) increased sharply with the increase of Pr content in Ce-Pr-O solid solution. In Ce-La-O solid solution, with the increase of La content , The product of visible light absorption intensity remained unchanged.