Nobel Metal- Metal Oxide Composite Nanoparticles: Controllable Synthesis, Growth Mechanism And Optical Properties

Metal- metal oxide heterogeneous nanoparticles have attracted extensive attention owing to their unique catalytic and optical properties. Therefore, their preparation and application have become one of research highlights in the field of nanotechnology. Nanomaterials with tunable size, morphology and composition often possess unique physical and chemical properties. To fabricate high-quality nanocrystals with well-defined shape and composition, the rational design of facile and environmental-friendly synthetic strategies is vital of significance. This dissertation focuses on the solution-based synthetic routes for noble metal and metal oxide nanostructures, as well as the catalytic properties of the as-prepared nanomaterials. This article contains the following sections:(1) Au@Zn O core-shell nanoparticles(NPs) with uniform size were successfully synthesized in a mixture solution of water and ethylene glycol through a seed-mediated approach by using Au nanooctahedra as seeds. We investigated the influence factors, which include reaction temperature, solvent, reduction reagent, surfactant, and concentration of the precursor, etc., for the synthesis of Au@Zn O core-shell NPs. The formation mechanism of Au@Zn O core-shell NPs was proposed based on our experimental results. Au@Zn O core-shell NPs with different sizes were prepared by tuning the experimental parameters. Moreover, both the thickness of Zn O shell and size of Au core can be rationally controlled. Further experiments explore the optical absorption ability in the visible range and photo catalytic properties.(2) Au@Cu2O, Au@Ag@Cu2O core-shell nanoparticles(NPs) with different morphology and composition were successfully synthesized in a mixture solution of water and ethylene glycol through a seed-mediated approach by using Au nanoparticles with diverse morphology, such as Au nanooctahedra, Au bipyramid and Au@Ag NRs as seeds. We investigated the influence factors, which include reaction temperature, solvent, reduction reagent, surfactant, and concentration of the precursor, etc., for the synthesis of heterogeneous nanoparticles. Moreover, both the thickness of Cu2 O shell and size of Au core can be rationally controlled. Further experiments explore the optical absorption ability in the visible range of the as-prepared nanomaterials.