26田中群--关于开展纳米尺度的表面(界面)物理化学研究的一些看法.pptVIP

厦门大学固体表面物理化学国家重点实验室 Interfaces Matel Oxide Aqueous Solution Semiconductor Alloy Polymer Organic Solution Origanic Film Biologic Film Melt Salt Cluster Superconductor Solid Electrolyte Place of heterogeneous Reaction Containing extremely small amount of species Varying temperature, pressure or electric field Solid / Liquid Interface Solid / Liquid / Gas Interface Surface Enhanced Raman Spectroscopy (SERS) Three factors influencing vibration frequency of molecule by the surface Three factors influencing vibration frequency of molecule by the surface Surface Enhanced Raman Scattering (SERS) EffectRaman signals from surface species on certain surfaces are about 106 times higher than that of the same species in the bulk phase Laser Confocal RamanMicroscope Acknowledgments （致谢） Bin Ren (任斌) De-Yin Wu (吴德印) Jian-Ling Yao (姚建林) Jing Tang (汤儆） Yun-Feng Xu（徐云峰） Feng-Ming Liu (刘峰名) Bing-Wei Mao (毛秉伟) Kai-Qi Huang(黄开启) National Distinguished Young Scientist Grant of China (国家杰出青年科学基金) Confocal Microscope for Single Molecule Detection 1 ?m3 = 10-15 dm3 = femto liter 10-9 M ? 1015 molecules/liter 10-9 M in 1 ?m3 ? 1 molecule How to increase the sensitivity to probe the interface Surface Enhanced Raman Spectroscopy (SERS) K. Kneipp, et al., Phys. Rev. Lett., 78, (1997)1667 Peak heights of the 1174 cm?1 crystal violet line for 100 SERS measure-ments (top), peak heights of the 1030 cm?1 Raman line measured from 1014 molecules of methanol in a silver colloidal solution (bottom). The single molecule events in the top trace appear at about 40 counts/sec, which corresponds to the signal level of 1014 methanol molecules in the bottom trace. The inserts display the Poisson and Gaussian statistics of the Raman signals for single and “many” molecules, respectively. x y z Incident light Light b a c 椭球粒子排布及光路示意图 d To detector Aspect Ratio: 2:1 Ni Co 入射光子能量 (eV) Cu Islands on smooth Cu Template Nanowire Network on smooth Cu 18