Prepartion And Properties Ofphosphotungstic Acid-Based Micro/Nano Composite Material

Polyoxometalate-based micro-/nanomaterials are a hot topic in the fields of polyoxometalates chemistry and materials chemistry. A series of micro/nano tubes of PW12/TiO2, CsHPW12/TiO2and PEI/PW12were prepared by template and sol gel method, and PW12/TiO2spherical clusters were prepared by sol gel method. The prepared micro/nano materials were characterized by IR, SEM, EDX, ICP and XRD. Catalytic oxidation of sulfur removal performance of PW12/TiO2and CsHPW12/TiO2micro/nano tubes and PW12/TiO2spherical clusters were studied. The main achievements obtained are given below.(1) A soluble and repeatable template of MgCO3·3H2O micro nanorods was prepared. A series of PW12/TiO2and CsHPW12/TiO2micro/nano tubes loaded with different amount of PW12were prepared by the template and sol gel method. The size of the micro/nano tubes can be controlled by tuning the morphology of MgCO3·3H2O template. Catalytic oxidation of sulfur removal performance indicates that the140mg of CsHPW12/TiO2tubes containing30%CsHPW12in weight can remove 87%of sulphur from20ml of octane simulation oil containing350ppm DBT and can be used for successive five tmes without significant reduce of catalytic activity.(2) A series of PW12/TiO2micro/nano spherical clusters loaded with different amount of PW12were prepared by a simple sol gel method. The sizes of the micro/nano spherical clusters can be controlled between200-600nm in diameter, and characterization proves the PW12-based micro/nano spherical clusters composite materials keep the original Kiggin type structure. Extraction combined with catalytic oxidation reaction confirms that20mL of octane simulation oil containing350ppm DBT can be removed to4.8ppm by70mg of30%PW12containing PW12/TiO2micro/nano spherical clusters samples.(3) Alternate deposition of positively charged PEI and negatively charged PW12on the surface of water-soluble Na2SO4nanowires templates results in formation of PEI/PW12nanotubes by simply dissolving Na2SO4nanowires templates in aqueous solution. The prepared PEI/PW12nanotubes were characterized by IR, SEM and EDX. This experiment proves that this kind of water soluble template method is a simple way to prepare nanotubes.