时间地点：2014年10月29日15:00  化学化工学院逸夫楼A315学术报告厅
报告人：Yugang Sun （孙玉刚）美国阿贡国家实验室教授
报告题目：Interfaced Heterogeneous Nanodimers
报告人简介：孙玉刚教授是美国阿贡国家实验室终身研究员，博士生导师，纳米材料研究中心主任。孙玉刚教授1996、2001年在中国科学技术大学分别获得学士与博士学位，2001-2006年先后在美国华盛顿大学、伊利诺伊斯大学从事研究工作，2006年后到美国阿贡国家实验室工作。孙玉刚教授多年从事新型金属纳米材料的构筑以及应用研究，近年来在贵金属纳米颗粒的控制合成、纳米金属空心结构的形成与演化、柔性可伸展纳米电路及器件、以及新型柔性氢气传感器的研制等研究方向上取得了创新性科研成果。孙玉刚教授已在权威国际刊物Science、Nature Nanotechnology、Nature Photonics, Nat. Commun., Proc. Natl. Acad. Sci., Angew. Chem. Int. Ed., Chem. Soc. Rev., Acc. Chem. Res., Adv. Mater., Nano Lett., J. Am. Chem. Soc.等上发表学术论文130余篇。孙玉刚教授2007年获得美国青年科学家总统奖（PECASE）；2011年荣获由汤森路透集团评选的全球最优秀顶尖100名材料学家与全球最优秀顶尖100名化学学家； 2014年荣获由汤森路透集团评选的Highly Citied Researchers in Chemistry and Materials Science与Highly Citied Researchers in Materials Science。
报告会摘要：Synthesis of interfaced nanoparticle dimers made of asymmetric compositions (i.e., interfaced heterodimers) is challenging because of the difficulty in manipulating the nanoparticles’ surface chemistries in order to control the assembly and/or growth of different nanoparticles.  In this presentation, I will discuss how to adopt the heterogeneous nucleation strategy for the synthesis of interfaced nanoparticle dimers made of different compositions. In the first part, a seed-growth of crystalline nanodomains on amorphous seed nanoparticles will be discussed.  In the second part, a seed-mediated, surface-confined epitaxial overgrowth strategy isintroduced to demonstrate the synthesis of high-quality interfaced dimers made of two different highly crystalline domains, e.g., Au-Ag heterodimers with varying sizes.  Au and Ag share a common face-centered cubic lattice and have nearly identical lattice constants, which facilitates epitaxial overgrowth and allows direct contact between the Au and Ag domains.  The interfaced Ag nanodomains can be chemical transformed to hollow nanoshells of other materials through a galvanic replacement reaction, resulting in the formation of interfaced dimers made of solid Au nanoparticles and hollow nanoshells.  Due to the direct contact between the two components in each interfaced dimer, strong coupling between them and the corresponding novel properties are expected.  For example, in the interfaced Au-Ag heterodimers with quantum sizes (diameters <10 nm) was observed an unusual enhancement of the characteristic au surface plasmon resonance and the emergence of a charge transfer plasmon across the au/ag domains, which together lead to broad-band absorption spanning visible to near-infrared wavelengths.

This work has been performed at the Center for Nanoscale Materials,a U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences User Facility under Contract No. DE-AC02-06CH11357.