表面修饰基团在过渡金属氧化物纳米颗粒上成键机理的原位非线性光学研究

项目名称： 表面修饰基团在过渡金属氧化物纳米颗粒上成键机理的原位非线性光学研究

项目编号： No.21303216

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 陆洲

作者单位： 中国科学院化学研究所

项目金额： 25万元

中文摘要： 表面修饰分子对人工调节功能型纳米材料的光电性能及化学与生物反应活性具有决定性的影响。长期以来，由于缺乏针对被埋藏的固-液界面的有效原位测量手段，溶液中纳米颗粒与表面修饰基团的成键机理尚未得到充分认识。过渡金属氧化物纳米颗粒的表面性质，如表面电位、氧化价态、尺寸、形状与晶面等，是如何影响配体分子与纳米颗粒表面之间的成键构型与键能的，一直是悬而未决的重要科学问题。界面非线性光谱具有表面选择性与亚单分子层的灵敏度，是研究纳米颗粒-溶液界面的分子结构与反应动力学的理想工具。本课题拟使用和频振动光谱，并结合纳米材料领域的常规表征手段，系统地研究溶液环境中膦酸、磺酸与羧酸配体分子在TiO2、CeO2以及Fe2O3纳米颗粒表面上的成键机理，深入了解表面分子结构与氧化物纳米颗粒的大小、表面电位、价态等性质之间的依赖关系。本研究对人工调控纳米材料和在分子层次上理解溶液中纳米催化反应动力学机理具有重要意义。

中文关键词： 和频振动光谱；纳米颗粒；表面修饰；成键构型；

英文摘要： Surface modification of functional nanoparticles by attaching ligand molecules to particle surfaces plays crucial roles in regulating the fundamental properties of the nanomaterials, such as the optical and electronic functionalities, the chemical and biological reactivity, as well as the dispersion stabilities in colloidal solutions. However, due to the lack of reliable in situ characterization tools for the buried solid-liquid interface, the nature of the ligand binding structure on nanoparticles in the aqueous environment is still not fully understood. For example, the surface of the transition metal oxide nanoparticles in the aqueous solution is often complicated and under dynamic changes. Up to date, little has been learned about how the fundamental surface properties of the transition metal oxide nanoparticles, including surface potential, oxidation states, particle size, shape, and surface crystal structures, are correlated to the binding structures and attachment affinities of the ligand molecules on nanoparticle surfaces. The second order nonlinear spectroscopy, including the second harmonic generation (SHG) and sum frequency generation (SFG), is known for its intrinsic surface-selectivity and sub-monolayer sensitivity. In addition, as optical spectroscopic probes, SFG and SHG do not require vacuum con

英文关键词： sum frequency generation vibrational spectroscopy；nanoparticle；surface modification；binding configuration；