Preparation, Characterization And Visible Light Drived Catalytic Performance Of Amino-Functionalized Cerium-Based Oxides

As an effective treatment of environment pollutants method, semiconductor photocatalytic oxidation technology has been widely studied. Being an important n-type photocatalyst, ceria (CeO2) is one of the most promising semiconductors which can realize visible light response and has better visible light absorption properties than that of TiO2 under the same conditions. In recent years, it has attracted comprehensive attentions of scholars and showed a good prospect of application for photocatalytic degradation of dye wastewater. But the photocatalytic degradation efficiency of single photocatalyst is relatively low, so it is of great significance to exploit composite photocatalysts. Up to now, the modification of TiO2 have been studied extensively. However, few studies of modification on CeO2 has been performed. Therefore, how to improve the photocatalytic properties still need to be studied.The aims of this study is to improve the photocatalytic properties of CeO2-based photocatalysts synthesized by a simple and cheap synthetic route. The following contents are investigated:(1) Mesoporous CeO2, Ce-Fe-O (0、5%、15%、25%) and Ce-Pr-O(0、5%、15% 25%) solid solutions with high content of hydroxyl groups were successfully synthesized using triblock copolymer P123 as template and Ce(NO3)3·6H2O, Fe(NO3)3·6H2O and Pr(NO3)3·6H2O as raw materials. Synthetic conditions of the ceria based oxide were screened and optimized.(2) Amino-functinalized ceria-based catalysts were prepared via modifying the optimizing samples using 3-aminopropyltrimethoxysilane (APTMS) as primary precursors. XRD, FT-IR, TEM, UV-Vis, XPS, Raman and N2 adsorption-desorption techniques were used to investigate the composition, structure and surface morphology of the resultant samples.(3) The photocatalytic activities of the prepared samples were evaluated by the decomposition of dyes (especially for acid red 14:AR14) under weak natural light irradiation. The factors affecting the photocatalytic effect such as medium pH, irradiation time, and acid dyes concentration were discussed in this study. At the same time, we have investigated other dyes such as Acid Orange 7 and Rodamine B. The results showed that the photocatalytic efficiency of animo functionalized mesoporous CeO2-based catalysts were much higher than that of mesoporous ceria, Ce-Fe-O and Ce-Pr-O. The decolorization rate of AR14 reaches about 90% in 3 h. The photocatalytic performance of mesoporous ceria based catalysts and amino-functionalized ceria based catalysts under the same conditions are as following:Ce-Pr-O> Ce-Fe-O> CeO2; NH2-Ce-Pr-O> NH2-Ce-Fe-O>NH2-CeO2.