Building Noble Metals Nanostructure And Applied Research Based On Au Decahedron

Noble nanostructures have attracted much attention during the past several decades owing to their promising applications in catalysis, optics, and bio-systems. As is well-known, their properties and applications are closely related with structures, shapes, sizes, and compositions. Therefore, numerous efforts have been put into their controlled synthesis. Seeded growth is the most widely used route to prepare core-shell and hetero-structure bimetallic NCs. Especially, it is an effective way to achieve core-shell bimetallic NCs which exposing high-index facets of the shell globe metal. Metallic NCs exposing high-index facets show significantly enhanced catalytic activity towards many reactions. In this dissertation, based on seeding-growth, noble metal nanoparticles with various shapes, structures and sizes were synthesized and the mechanism was studied. The main research work as following:(1) Using Au decahedra as seed, HAuCl4as precursor, prepare nanobipyramid Au. Through control the reaction conditions such as reaction temperature, reaction time, the amount of HAuCl4, the size of the seeds, and so on, to find a best condition to achieve nanobipyramid. At last, we achieve a best reaction conditions to prepare nanobipyramid Au. And explore the growth process of nanobipyramid Au, push out the reaction mechanism. Using2-naphthalene as probes to study its surface enhanced Raman scattering (SERS) properties which confirmed that the nanobipyramidal Au has strong Raman enhanced performance.(2) Also use Au decahedra as seed, KPdBr4as precursor, synthesis of Au@Pd nanorices. In the reaction, adding N2to remove the air, to prevent the CI/O2etching Au seeds. The Au@Pd nanorices which we prepare have high index, so that have good oxidation reduction effect of formic acid.(3) Surfactant-free synthesis of carbon-supported Au as seeds. Carbon-supported Au@Pt nanostructures prepared using different ratios of Pt and Au. In the catalytic properties in Oxidation of methanol. These prepared catalysts show higher catalytic activity and stability in the electro-catalytic Oxidation of methanol.