留学美国签证研究计划模板大全

留学美国签证研究计划模

板大全

Descriptions of the research plan

Title: Synthesis, Formation Mechanism, and Properties of Different Metal/Metal Nanostructures Keywords: Multi-Shell Nanostructures, Ionic Liquids, Electrochemistry, Multi-Functionality,

Porous Metal Materials, Low-Dimensionality, Green Chemistry Objectives: This program is to develop a novel method for fabricating heterogeneous or alloyed different metal/metal low-dimensional nanostructures, for example, multi-shell or porous Ag-Au nanowires, nanorods, and nanocubes using an ionic liquid as both the solvent and shape-inducing template. Synthesis of ionic liquids (ILs) with different alkyl chains and functional groups, as well as the formation of different metal/metal nanostructures with new properties are involved in this research plan. Alloyed or heterogeneous multi-shell nanostructures are generated by utilizing electrochemical (electroless) deposition or a simple galvanic replacement reaction in ILs. By controlling the size, shape, composition, crystal structure and surface properties of these structures, it enables us not only to uncover their intrinsic properties, but exploit their formation mechanism in ILs media, as well as their applications in catalysis, surface-enhanced Raman scattering (SERS), sensors, porous electrodes, etc. This green chemistry process also may be extended to synthesize other organic and inorganic nanostructures with novel properties, morphology and complex form. State-of-the-art

Metal nanostructures have numerous applications as nanoscale building blocks, templates, and components in chemical and biological sensors, as well as electronic/optical devices, due to their interesting optical, catalytic and electrical properties that depend strongly on both size and shape. Over the past decade, impressive progress has been made towards the fairly good shape and size control of metal nanostructures [1][2]. For noble metals, more emphasis is placed on tuning the novel shape-dependent properties of these nanostructures in contrast to the size-dependency. A variety of metallic building blocks with unique properties have been synthesized including cubes [3][4], prisms [5], disks [6], and hollow nanostructures [7]. Currently the interests migrate to the synthesis and application of more complex structures with different metals, such as multi-shell and heterogeneous nanostructures having new properties[8][9], coupling a conception for optimizing preparative strategies in an environmentally benign system[10]. Therefore, besides creating novel nanostructures with unique properties, a problem arising from the utilization of volatile or poisonous organic solvents and additives is of much concern in view of cleaner technology throughout both industry and academia.

Most of the current shape selective synthesis of metal nanostructures that their optical properties are markedly affected by their shape and aspect ratio are centered either on a solid substrate by physical methods or in aqueous or organic media through chemical procedures [2]. For instance, complex and highly regular crystalline silver inukshuk architectures can be produced directly on a germanium surface through a simple galvanic displacement reaction that only three ingredients were required: silver nitrate, water, and germanium [11]. Despite these advancements, however, limited reports have been reported on how the particle morphology and dimensionality could be