报告时间：7月14日（周一），下午14:00    报告地点：生物楼学术报告厅 

　　报告人：孙玉刚

　　美国阿贡国家实验室 

　　Center for Nanoscale Materials, Argonne National Laboratory 

报告简介： 

Nanoparticles made of noble metals such as silver and gold exhibit strong optical absorption due to their surface plasmon resonance (SPR) that corresponds to the collective oscillation of surface conduction electrons in response to the incident electromagnetic waves.  As the nanoparticles are smaller than 20 nm the interfacial quantum effect may take place to influence the SPR of the nanoparticles.  For example, the monodispersed silver nanoparticles synthesized via a well-defined chemical reduction process exhibit an exceptional size-dependence of SPR peak positions: as particle size decreases from 20 nm the peaks blue-shifts but then turns over near ~12 nm and strongly red-shifts.  Theoretic modeling and calculations reveal that the surface chemistry corresponding to the interactions between the capping molecules and the surface silver atoms in the nanoparticles become pronounced in determining their optical properties because the surface silver atoms represent a significant fraction of the total number of atoms in small nanoparticles.  Such surface chemistry reduces the density of conduction band electrons (i.e., free electrons) in the surface layer of metal atoms, thus consequently influences the frequency-dependent dielectric constant of the metal atoms in the surface layer and the overall SPR absorption spectrum.  Another class of hybrid silver-gold nanoparticles will also be discussed.  The coupling between the SPR of the silver and gold components leads to very interesting optical signals that can be interpreted with classical plasmonics in combination with a quantum-corrected model.  A comprehensive understanding of the relationship between interfacial coupling/chemistry and optical properties will be beneficial to exploit new applications of small colloidal metal nanoparticles, such as colorimetric sensing, electrochromic devices, surface enhanced spectroscopies, and photocatalysis. 

报告人简介： 

Publication, Patent and Presentation Summary 

　　Over 120 peer reviewed journal articles, 14 patents, 58 invited talks; Total citation > 21900, H-factor=45 

　　Top 100 Materials Scientists with highest impact score (2000-2010), Rank #5, Thomson Reuters 

　　Top 100 Chemists with highest impact score (2000-2010), Rank #62, Thomson Reuters 

Professional Society Memberships 

　　Member of the Materials Research Society (MRS) 

　　Member of the American Chemical Society (ACS) 

　　Member of the American Association for the Advancement of Science (AAAS) 

　　Member of the American Nano Society (ANS) 

Research Interests 

　　？ Design and synthesis of hybrid nanostructures with increased complexity and functionalities 

　　？ Investigation of novel properties of synthesized nanostructures in the context of nanophotonics, photocatalysis, sensing, and energy storage/conversion 

　　？ Development of in-situ synchrotron x-ray techniques and in-situ electron microscopic techniques for real-time probing reaction kinetics and phase dynamics involved in the synthesis of colloidal nanoparticles and for in-operando characterizing the corresponding devices under real operating conditions 

Education 

　　Ph.D., Chemistry, University of Science and Technology of China (USTC), 2001 

　　BS, Chemistry, University of Science and Technology of China (USTC), 1996 

Professional Experience 

　　2010.01 – present    Scientist, Nanoscience, Nanophotonics Group, Center for Nanoscale Materials, Nanoscience and Technology Division, Argonne National Laboratory 

　　2006.08 – 2009.12    Assistant Scientist, Nanoscience, Nanophotonics Group, Center for Nanoscale Materials, Argonne National Laboratory 

　　2004.01 – 2006.07    Postdoctoral Fellow, The University of Illinois at Urbana-Champaign, Urbana, IL 

　　2001.03 – 2003.12    Postdoctoral Fellow, University of Washington at Seattle, Seattle, WA 

报告联系人：人事处 孙军（9556）