Synthesis And Property Study Of Nanoparticles/Carbon Composite Materials

Nanoparticles (NPs) in oil phase have been widely used in the fields of catalysis and energy storage because of their adjustable morphology, size, monodispersion and good stability. Novel carbon materials such as active carbon, graphene, have attracted the attention of researchers because of the unique structure and excellent properties. Combining of nanoparticles and carbon materials can develop the superiorities of both at the same time. By combining carbon materials and photocatalysts, the high absorbent ability and large specific surface area of carbon materials can be used to improve the adsorption capacity towards pollutants of catalyst, and further improve the photocatalysis activity. Besides, the excellent electrical conductivity of carbon materials like graphene can accelerate the electronic transmission of materials, which can improve the activity. The thesis mainly contains two parts of work around the composites of nanoparticles and carbon materials:first, Au NPs and TiO2 nanorods (NRs) in organic phase were assembled through emulsion based bottom-up self-assembly (EBS) method, followed by the carbonization of surfactant which can form carbon covered nanocomposite mesoporous microspheres. The selective adsorption of the carbon enable the excellent selective photocatalysis of the microspheres. Second, a universal method has been developed to synthetize NPs/graphene aerogel composites. Making use of the hydrophobic surface and hydrophilic edges of graphene oxide, the cyclohexane dispersion of NPs and the water dispersion of graphene oxide were mixed intensively. The equally load of NPs on graphene can be realized. At the same time the cyclohexane drops can be used as templates in the form of graphene aerogels. The structure of graphene aerogel loaded NPs improve the properties of NPs. The details are as follows:The Au NPs and TiO2 NRs has been synthesized through solvent thermal route. Using EBS methods to assemble them into the colloidal spheres with the size of about 100nm, which are later calcined under N2 flow to form C/Au/TiO2 nanocomposite mesoporous microspheres. The composite microspheres, which have large specific surface area, the negative charged surface and the mesoporous structure, have significant selective adsorption and photocatalysis. Meanwhile, the surface plasmon resonance of Au nanoparticles can improve the photocatalysis activity of the materials.A general synthetic method of graphene aerogel loaded NPs has been developed. Making use of the hydrophobic surface and hydrophilic edges of graphene oxide, the NPs with hydrophobic surface were loaded on the surface of graphene. The cyclohexane drops were used as templates to form pores. The graphene oxide sheets self-assembled to form hydrogel structure in the process of hydrothermal. Using this method, the Au, TiO2, CeO2, Fe3O4/graphene aerogel composite mesoporous materials have been successfully synthesized. The TiO2/graphene aerogel have better adsorption and photocatalysis activity than the pure TiO2 NRs.