The Structure Design Preparation And Properties Of The "Sandwich" Magnetic Clay Photocatalytic Composite

TiO2photocatalytic oxidation has great potential in dye wastewater treatment. It has been applied for high biological toxic and difficult to degradate pollutants, because it can effectively degrade organic pollutants into mineralization, and has no secondary pollution. Although tinanium dioxide (TiO2) has a strong photocatalytic activity, the nano-scaled TiO2particles prone to agglomerate into larger ones, thus reducing the catalytic activity. Meanwhile, nanoparticles are difficult to be separated and recycle. So it needs to select the appropriate carrier for nano TiO2particles to be immobilized to solve the problem of aggregation. Montmorillonite(MT) has been regarded a research hotspot in recent years due to its interlayer cation exchange characteristics. In this study, an idea on designing magnetic clay photocatalytic composite based on MT is proposed is proposed. A sandwich-type of magnetic clay photocatalytic composite was prepared on natural montmorillonite by using the assemblation with application of surfactant CTAB on montmorillonite clay in aqueous solution. First, Fe polycations was prepared by mixing FeCl3·6H2O and NaOH as raw meterials. Then, Fe-pillared montmorillonite was got through ion exchange between Fe polycations and Na+. After that, the magnetic modified clay was obtained after heat treatment under a nitrogen atmosphere. The thermal analysis, X-ray diffraction, magnetometer characterization results shows that nano-scaled iron oxide can effectively stay in the clay interclayer when the samples calcined under N2atmosphere. The nano particles of Iron oxide composite by two types of a-Fe2O3and Fe3O4crystal phase, the Fe3O4phase was the magnetic phase.Secondly, magnetic clay photocatalytic material was prepared with MT as a carrier by immobilizing nano-TiO2on montmorillonite layer surface through regulation of CTAB. CTAB-DEA-TiO2self-assembly nano-particles can improve the nanao-titanium oxide particles highly dispersed on the surface of MT, which is expected to solve the problem of agglomeration. The results show that the specific surface area of the clay materials significantly increased, which helps to enhance the adsorption and catalytic properties of the composites to pollutants.In order to evaluate the adsorption and photocatalytic properties of the composites, the synthesized magnetic clay photocatalytic composites are applied to degradate methyl orange wastewater. The results show that the synthesized samples has good adsorption properties and catalytic performanceon degradation of methyl orange solution. A microwave discharge...