Au/Ag团簇紫外-可见光吸收谱调控规律和物理机制的理论研究

Due to unique adsorption spectra, size-dependent electrochemical properties and the high chemical stability, Au/Ag clusters have become an ideal model to explore physical phenomena in a wide range. There obtained plenties of experimental data about the influence of the geometry structure and surrounding environment of Au/Ag clusters on their UV-vis adsorption spectra during the past few years, but theoretical studies of the internal mechanism are still quite scarce. In this project, we proposed to extensively investigate UV-vis adsorption spectra of Au/Ag clusters by time-dependent density fundational theory based first-principle calculations. Firstly, we explore tuning rules of UV-vis adsorption spectra of decorated Au/Ag clusters, through varying functional groups and adsorption concentration of organic molecules. Secondly, we search stable configurations of Au/Ag alloy clusters with different ingredients and atom distributions, compare the differences of UV-vis adsorption spectra, and then build the initial physical picture of noble metal clusters’ adsorption spectra tuned by alloy effect. Finally, we try to construct the multi-dimensional nanostructures of large organic molecules and alloy clusters (or pure metal clusters), and investigate the effect of organic molecule-cluster bonding type and cluster coupling on UV-vis adsorption spectra of Au/Ag clusters. This project is supposed to provide the novel and abundant theoretical guidance to experimental design and applications of noble metal compound clusters.

Au/Ag 纳米团簇由于其独特的光吸收性质、尺寸依赖的电化学性质以及较高的化学稳定性，已成为探索较大范围内物理现象的理想模型。近年来，Au/Ag 纳米团簇的结构及外围环境变化对其紫外-可见光吸收谱的影响已经取得丰富的实验数据，但光谱调控的内在机制研究仍相当匮乏。本项目拟运用基于第一性原理的含时密度泛函理论对Au/Ag 纳米团簇的紫外-可见光吸收谱进行系统研究。首先通过改变有机分子官能团类型和吸附数量，探索有机分子修饰对贵金属纳米团簇光吸收谱调控的拓扑规律；其次按照特定规则，构建不同组分和原子分布的Au/Ag合金团簇，对比其紫外-可见光吸收谱的差异，初步建立合金效应对团簇光吸收谱调控的物理图象；最后构建有机大分子和合金团簇（或纯金属团簇）多维复合结构，研究有机分子-团簇键和类型、团簇耦合对光吸收谱的影响。本项目可为有机分子和贵金属复合团簇的实验设计和应用提供新颖而丰富的理论依据。