Design And Preparation Of POM-embedded Porous Materials And Their Photocatalytic Properties

Polyoxometalates?POMs?have numerous potential applications due to their rich composition,structure as well as unique physical and chemical properties.The oxygen-rich nature and high negative charge of the POMs make them soluble in most polar solvents.So it is usual to embed the POMs into the holes of porous materials before using catalysis.On the one hand,it is advantage to facilitate the recycling of the catalyst and avoid waste;On the other hand,the obtained catalysts may show better catalytic performance than that of the single component.Based on the above,we designed and synthesized two kinds of new porous materials with POM embedded,and studied the visible photocatalytic performance.1.We introduce K₆[?-AgPW₁₁O₃₉] into NH₂-MIL-101?Al?by virtue of an incipient wetness impregnation method,and Ag/PW₁₁O₃₉-doped AgCl@NH₂-MIL-101?Al?was obtained by UV reduction.The coordination interaction between POM unit and Ag+,and the confined cavity of NH₂-MIL-101?Al?depress the fast reaction between Ag+ and Cl-ion and the over agglomeration of AgCl crystalline,resulted in ultrafine Ag/POM-AgCl nanoparticles.The composition and morphology of the composites were characted by X-ray powder diffraction,infrared spectroscopy,X-ray photoelectron spectroscopy,X-ray energy dispersive spectroscopy,scanning electron microscopy,and transmission electron microscopy and so on.Studied on the photocatalytic activity of Ag/PW₁₁O₃₉-doped AgCl@NH₂-MIL-101?Al?found that it showed excellent catalytic activity for dye degradation under visible light.The mechanism of the photocatalytic process has also been studied in detail.2.Through immersing method we introduce?NMe₄?₇PTi₂W₁₀O₄₀ into the mesoporous of SiO₂-NH₂,and then ZIF-8 was grown on the obtained nanoparticles.The composition and morphology of the materials were analyzed by a series of characterization methods,and the photocatalytic performance of each component was compared.Compared with POM,SiO₂-NH₂ and ZIF-8,after the combination of POM and carrier,its catalytic performance exceeded the single component.