Direct visual evidence for chemical mechanism of SERRS of pyrazine adsorbed on Ag nanoparticle via charge transfer

作者：Luo, Jing; Wang, Peijie^*; Fang, Yan

来源：Vibrational Spectroscopy, 2014, 70: 162-167.

DOI：10.1016/j.vibspec.2013.12.003

• Surface-enhanced resonance Raman scattering (SEARS)
• Charge transfer (CT)
• Charge redistribution (CR)
• Charge difference densities

In this paper, the chemical enhancement of surface-enhanced resonance Raman scattering (SERRS) of pyrazine adsorbed on Ag nanoparticles through charge transfer was experimentally and theoretically investigated. Based on the calculations by density functional theory (DFT) and time-dependent OFT (TD-DFT), we theoretically analyzed the absorption spectra and SERS spectrum of the S-complex of pyrazine-Ag-20. The charge transfer in the process of resonant electronic transitions between adsorbed molecule and metal cluster can be visualized by the method of charge difference density. It is a direct evidence for the chemical enhancement mechanism of SERRS of pyrazine molecule adsorbed on Ag nanoparticle via charge transfer between molecule and metal. Additionally, the intracluster charge redistribution was also considered as an evidence for the electromagnetic enhancement. By comparing the experimental and theoretical results, it was demonstrated that the SERRS of the pyrazine molecule absorbed on silver clusters in different incident wavelength regions is dominated by different enhancement mechanisms via the chemical and electromagnetic enhancements.

• 出版日期2014-1
• 单位首都师范大学