物理化学学报2011，Vol.27Issue(6)：1335-1340,6.
理论研究Ag/MPH/TiO2体系的SERS光谱化学增强机理
Theoretical Investigation of Chemically Enhanced Mechanism of SERS Spectroscopy for Ag/MPH/TiO2 System
摘要
Abstract
A chemically enhanced mechanism of surface-enhanced Raman scattering (SERS)spectroscopy was investigated using density functional theory (DFT).We studied the Raman spectra of the Ag13/MPH and Ag13/MPH/TiO2 systems under 514.5 nm excitation.We found that the intensities of the non-totally symmetric vibration modes were selectively enhanced after TiO2 was introduced into the Ag13/MPH system.By analyzing the ground state and excited states of the charge transfer (CT) complex we found that the system gave a photoinduced CT state from Ag to the MPH-TiO2 complex when the excitation wavelength exceeded the optical absorption threshold (635 nm) of the MPH-TiO2 complex.The selective enhancement of the b2 modes in the SERS spectra probably originates from the Herzberg-Teller mechanism through the coupling of the corresponding modes with the CT transition.Our theoretical results support the experimental results and also define the adsorption threshold of the CT complex clearly while providing an intelligible physical explanation for the laser wavelength-dependent SERS phenomenon.关键词
表面增强拉曼散射/密度泛函理论/电荷转移复合物/化学增强机理Key words
Surface-enhanced Raman scattering/ Density functional theory/ Charge transfer complex/ Chemically enhanced mechanism分类
数理科学引用本文复制引用
孙磊,白福全,张红星..理论研究Ag/MPH/TiO2体系的SERS光谱化学增强机理[J].物理化学学报,2011,27(6):1335-1340,6.基金项目
国家自然科学基金(20973076,21003057)资助项目 （20973076,21003057）
