多枝状贵金属纳米晶的可控合成、性质及其生长机理的研究

项目名称： 多枝状贵金属纳米晶的可控合成、性质及其生长机理的研究

项目编号： No.21203130

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理化学

项目作者： 马艳芸

作者单位： 苏州大学

项目金额： 26万元

中文摘要： 贵金属纳米晶独特的电学、光学和催化等性质通常与其尺寸、形状和表面结构等因素密切相关。实验和理论计算都证明非球形Au、Ag纳米晶由于电磁场的各向异性分布而在表面等离子共振（SPR）和表面增强拉曼散射（SERS）性质上优势显著。其中，具有多个尖锐分枝的Au纳米晶的SPR带可调至近红外区域，尖锐分枝的"避雷针效应"也使其SERS大幅增强。这些特性使多枝Au纳米晶在生物医学领域（如光热治疗）有广泛的应用前景。本项目通过控制多枝Au纳米晶的生长动力学，最终得到几种尺寸均匀、SPR和SERS性质优异的多枝Au纳米结构，并以此为模板生长具有其他贵金属壳层的多枝双金属纳米晶。通过精确调控分枝长径比、尖锐度等，系统研究多枝结构与其性质间的关系。此外，利用高分辨透射电镜和原位X射线吸收精细结构谱，研究分枝表面原子结构变化和多枝纳米晶的生长机理，从而指导特殊形状贵金属纳米晶的设计合成。

中文关键词： 多枝的；贵金属纳米晶；XAFS；生长机理；催化性能

英文摘要： Noble metal nanocrystals have exhibited remarkable physical and chemical properties, such as electronic, optical and catalytical properties, which are closely related to their size, shape, surface structure and so on. Experimental and theoretical calculations have proven that nonspherical Au and Ag nanocrystals show outstanding properties on both surface plasmon resonance (SPR) and surface enhanced Raman scattering (SERS), due to the anisotropic distribution of the electromagnetic field. Particularly, Au nanocrystals containing multiple sharp branches have SPR bands that are tunable into the near-infrared region, and show great SERS enhancements resulting from the "lightning-rod effect" of sharp branches. Therefore, multi-branched Au nanocrystals have exhibited promising biological applications, such as biosensors, diagnostics and photothermal therapy. In this proposal, we'll control the growth kinetics of branched Au nanocrystals to obtain several types of multi-branched Au nanostructures with large aspect ratio and sharp branches, which show superiority on SPR and SERS properties. Furthermore, the branched bimetal nanocrystals of a core-shell structure will be controlled synthesized, where multi-branched Au nanocrystals act as "template" or "crystal seeds" and other novel metal (such as Ag, Pt and Pd) can gro

英文关键词： branched；noble metal nanocrystals；XAFS；growth mechanism；catalytic property