Dumbbell Nanocomposites: Controlled Chemical Synthesis and Catalytic Applications

本项目旨在开发一种结构类似哑铃的新型复合纳米材料，该材料具有两种不同的功能纳米粒子单元，一种是磁性铁氧体（MFe2O4）、铁、钴、镍、铁-镍或钴-铁，另一种是金属金、银、铂或钯。这两个功能单元通过一个晶体在另一个晶体上的外延生长在物理上联系在一起。两个粒子之间的外延连接可以被认为是一个纳米级的结，一个纳米粒子中的电子能够通过界面转移到另一个纳米粒子。这种结效应可以改变哑铃结构中两种粒子的电子结构，从而获得单组分纳米粒子所不存在的新的物理和化学性质。本文所实现的对复合纳米结构的尺寸、形状和互连的合成控制，将允许对哑铃结构中的结效应进行微调，从而促进具有最佳催化应用性能的先进复合纳米材料的合理设计和合成。摘要本研究代表了固体复合纳米结构研究的一个新方向。它将为PI在布朗大学本科和研究生授课的两门课程——固态化学和纳米材料：合成与应用——提供新的内容。复合纳米结构及其合理的研究方法将进一步丰富布朗大学化学、物理、工程和生命科学系的纳米科学和纳米技术专业。拟议的研究将为理工科学生的教育做出重要贡献，以迎接未来纳米科学和纳米技术的挑战。研究成果将在课堂上及时传播给布朗大学的理工科学生，并通过会议/研讨会演讲和期刊/专利出版物向科学界和公众传播。

Technical AbstractThis project aims to develop novel composite nanomaterials with a structure similar to the dumbbell that has two different functional nanoparticle units with one being magnetic ferrite (MFe2O4), iron, cobalt, nickel, iron-nickel, or cobalt-iron, and the other metallic gold, silver, platinum, or palladium. These two functional units are physically linked by epitaxial growth of one crystal on another. The epitaxial linkage between two particles can be considered as a nanoscale junction, and electrons in one nanoparticle are capable of transferring across the interface to another nanoparticle. This junction effect can modify the electronic structure of both particles in the dumbbell structure, leading to novel physical and chemical properties that do not exist in the single component nanoparticles. The synthetic control in size, shape and interconnection of the composite nanostructures, achieved in this proposal, will allow the fine tuning of the junction effect in the dumbbell structures, facilitating the rational design and synthesis of advanced composite nanomaterials with optimum properties for catalytic applications.Non-technical AbstractThe proposed research represents a new direction in the study of solid-state composite nanostructures. It will provide new contents for both Solid State Chemistry and Nanoscale Materials: Synthesis and Applications, two courses the PI has been teaching in Browns undergraduate and graduate classes. The composite nanostructure and the rational approach to it will further enrich the Nanoscience and Nanotechnologyeducation programs in Browns Chemistry, Physics, Engineering and Life ScienceDepartments. The proposed research will contribute an essential part to the education ofScience and Engineering students to meet tomorrows challenge in Nanoscience andNanotechnology. Timely dissemination of the research results will be to theScience/Engineering students at Brown during the class hours, and to the scientific community and general public through conference/seminar presentations andjournal/patent publications.