Design,Synthesis And Application Of One-dimensional Noble Metal Heteronanostructures

Nobel metal nanostructures have great potential in many application fields for their unique small size effect, optical effect, surface effect, good biocompatibility,excellent electrical conductivity and catalytic activity and so on. The composition,size and shape of them are important parameter in determining their electrical, optical,magnetic and chemical properties to a great extent. Heterostructured nanomaterial not only joint different domine with diverse functions, but also give a new or improved physical and chemical properties. In the paper, we synthesized a series of one-dimensional nanostructures by using Te nanowires as template. Considering that different composition have different characteristic, we studied properties of these new material in different application objects. Additionally, these materials were characterized by various methods, and related discussion and analysis about their synthesis processes and the relationship of the property and structure were presented.The mainly content of the study is summarized in the following words:1. Porous platinum nanotubes were synthesized by using tellurium nanowires as sacrifice template in aqueous solution at room temperature, and the related process and reason was studied. In addition, their peroxidase-like activity was studied. The result shows that porous platinum nanotubes have outstanding intrinsic peroxidase-like activity. The nanotubes have a great potential to be used as a peroxidase mimetic in biotechnology and immunoassay.2. Novel Ag/Pd heterostructured nanotubes were synthesized to overcome the general problem in lable-free in situ SERS monitoring, that is it is hard to keep a high catalytic activity and SERS activity at the same time. In the heterostructure, two different function parts are joint together and both of them are exposed to the solution.The chitosan-assisted synthesis method can be used to prepare other Ag-including heterostructured nanocrystals. Moreover, the nanostructures was used in the SERS monitoring successfully.3. A quasi-one-dimensional Au/PtAu heterojunction nanotubes were synthesized and their electrocatalytic activity were studied in oxygen reduce reaction. In thesynthesis, Te nanowires were used as partial sacrifice template to form Pt@Te core-shell one dimensional nanostructure before using Au precursor. The catalyst showed enhanced catalytic activity than porous Pt nanotubes and commercial Pt/C. In addition, this method provides a facile strategy for the synthesis of desirable hetero-nanostructures with controlled size and shape by utilizing an intermediate template.4. Pd nanotubes covered by high-density Au-islands were synthesized, in which abundant exposed Pd-Au heterojunction interfaces are present and the content of element Au can be easily controlled. The optimized nanostructures showed remarkably enhanced activity for catalyzing different alcohols in alkaline media than commercial Pd/C. The mass activity of them is 9.66, 1.83 and 4.60 A mg-1metal towards the electrooxidation of ethanol, glycerol and ethylene glycol in alkaline media, which is about 6, 4 and 7 times that of Pd/C, respectively. Additionally, a model was proposed to explain the relationship between the structure and the catalytic activity.The study provides a new strategy for the design of heterostructured catalyst having higher activity.