Dumbbell Nanocomposites: Controlled Chemical Synthesis and Catalytic Applications

技术摘要本项目旨在开发新型复合纳米材料，其结构类似于哑铃，具有两个不同功能的纳米粒子单元，一个是磁性铁氧体(MFe2O4)、铁、钴、镍、铁-镍或钴-铁，另一个是金属金、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。两个纳米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状结构中两个粒子的电子结构，从而产生单一组分纳米粒子所不存在的新的物理和化学性质。该方案实现了对复合纳米结构尺寸、形状和互连的综合控制，可以微调哑铃结构中的结效应，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。它将为固体化学和纳米材料：合成和应用提供新的内容，这两门课程一直是PI在布朗大学本科生和研究生班级教授的。这种复合纳米结构及其合理的方法将进一步丰富布朗化学、物理、工程和生命科学系的纳米科学和纳米技术教育计划。这项研究将对理工科学生迎接未来纳米科学和纳米技术的挑战起到至关重要的作用。研究成果将在上课时间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普通公众传播。

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.