The Pore Structure Containing Acid Composite Photocatalytic Materials Preparation And Performance Study

Three types of the solid photocatalytic materials such as hybridcatalyst K5M(H2O)PW11O39-APS-SiO2 (abbreviated PW11M-APS-SiO2,M= Ni/Co,APS = (C2H5O)3SiCH2CH2CH2NH2,SiO2 = MCM-48,MCM-41,SIO-7); mesoporous composite material H3PW12O40/TiO2 (amorphous) andH6P2W18O62/TiO2(anatase phase) were prepared by the self-assemblymethod, sol-gel and programmed temperature hydrothermal methods.As-synthesized materials are novel, water-insoluble, photochemicallyactive and porous. UV-vis diffuse reflectance spectra (UV/DRS), infrared(IR) spectra, raman spectra, 31P MAS NMR, ICP-AES, powder X-raydiffraction (XRD), TEM and nitrogen adsorption analysis were used tocharacterize the composition, structure, morphology and surfacephysicochemical properties of as-prepared solid photocatalytic materials,indicating that the primary polyoxometalate (POM) structures remainedintact in as-prepared composites, and the composites exhibited porousstructures. The average pore size of the hybrid catalyst PW11M-APS-SiO2is 5.4-40.3 nm, the average pore size of the mesoporous composite materialH3PW12O40/TiO2 is 3.06 nm, and H6P2W18O62/TiO2 (anatase phase) havebimodal pore systems (micro-mesoporosity) with pore size at 0.6 and 4.0nm. In addition, compared with starting POMs, BET surface areas of thesolid photocatalytic materials have been improved in the different extents. Photocatalytic activities of as-synthesized composites were studiedvia the following model reactions, e.g., photodegradation of the aqueousdye, the pesticide hexachlorobenzene (HCB) and methylparathion (MPT).It has shown that aqueous organics can be degraded by the hybrid catalystPW11M-APS-SiO2 under near-UV irradition and by mesoporousH3PW12O40/TiO2 (amorphous) and H6P2W18O62/TiO2 (anatase phase) undervisible-light irradition. The photocatalytic activity of the solidphotocatalytic materials is attributed to the structure of POMs, unique ３东北师范大学硕士论文physicochemical properties of the porous materials, sensitized effect of thedye molecular adsorbed on the surface of the catalyst, and the synergisticeffect yielded by the combination of POM and TiO2.