Design Synthesis And Photocatalytic Property Of Fe₃O₄-based Nanocomposite

In recent years, with the rapid development of high-tech materials performance increasing demands, conventional single material is no longer meet the demand for the development and composites become the alternatives. Nanocomposite is an important aspect of an application of nanotechnology in nanomaterials. Nanocomposites combine the properties of the two or more materials through their synergies and break the boundaries between the various materials, with the excellent performaces without traditional composite materials, such as optical, electrical, magnetic, thermal, surface active sensitive features and high stability, which can meet a variety of special to demand good research and application valune. Fe3O4nanoparticles possess quantum size effect, volume effect, macroscopic quantum tunneling effect, specific surface effect, soperparamagnetic of special physical and chemical properties, and have a wide range of applications in the biomedical, biological separation, the light catalytic, magnetic fluid, microwave absorption, so the magnetic nanomaterials become the research focus. But, Fe3O4nanoparticles have a higher surface energy and a larger surface area, while the magnetic particles exist between dipole attractive interactions. So Fe3O4nanoparticles are easier agglomeration and sedimentation than no-magnetic nanoparticles. According to a large number of reported, the surface of Fe3O4nanoparticles coated with a larger of the inorganic inert material or a polymer can effectively improve the dispersion of the Fe3O4nanoparticles, while due to the synergisitic effect between the materials to improve the original inorganic inert material and polymer physicochemical natures.The main work of this paper synthesized Fe3O4@TiO2, Fe3O4/Ag and Fe3O4@SiO2@Ag nanocomposites on the basis of monodisperse Fe3O4nanoparticles and its photocatalytic properties were studied, which characterized by XRD, TEM, Uv-vis and so on. The details are as follow:1. The preparation, characterization and photocatalytic property of Fe3O4@TiO2core-shell nanocompositesThe visible catalyst of core-shell structural Fe3O4@TiO2nanocomposites were prepared by the solvothermal crystallization method assisted hydrolytic precipitation method. The samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Uv-visible spectroscopy instrument (Uv-vis). The visible light photocatalytic properties of magnetic nanocomposites for methylene blue were studied.2. The preparation, characterization and photocatalytic property of Fe3O4/Ag heterogeneous nanocompositesOn the basis of previous work, the small particles size Fe3O4/Ag heterogeneous nanocomposites were prepared, reducing silver ammonia solution at the room temperature by PVP in the inorganic/organic hybrid phase, and the Fe3O4nanopartiecls as seeds. The samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Uv-visible spectroscopy instrument (Uv-vis). The visible light photocatalytic properties of magnetic nanocomposites for methylene blue were studied.3. The preparation, characterization and photocatalytic property of Fe3O4@SiO2@Ag core-shell nanocompositesIn this chapter, layer by layer structural Fe3O4@SiO2@Ag nanocomposites were previously prepared at the room temperature on the basis of iron oxide. The samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Uv-visible spectroscopy instrument (Uv-vis). The degradation of magnetic nanocomposites for methylene blue were studied.