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论文类型：期刊论文

发表时间：2017-01-01

发表刊物：RSC ADVANCES

收录刊物：SCIE、EI

卷号：7

期号：20

页面范围：12170-12178

ISSN号：2046-2069

摘要：In this study, we theoretically investigated the Raman and absorption spectra of pyrazine adsorbed on Au5Al5 bimetallic nanoclusters by a time-dependent density functional theory (TD-DFT) method. The surface-enhanced resonance Raman scattering (SERRS) spectra of pyrazine absorbed on different isomers and sites of the Au5Al5 cluster were simulated. The visualization of orbital transitions in electronic transitions was used to analyze the enhancement mechanism of SERRS spectroscopy. Compared with those of isolated pyrazine excited at 598 nm, the SERRS of pyrazine-Au-Au(4)Al(5-)a excited at the same incident light can be enhanced on the order of 10(4), which is a typical charge transfer (CT) resonance excitation and charge transfer from substrate to pyrazine. Due to the fact that the intensity of ultraviolet SERRS can be significantly enhanced to 1.2 x 106 A(4) per amu for pyrazine-Au- Au4Al5-a model at 280 nm, the Au5Al5 cluster may be a good candidate for research of the ultraviolet SERRS materials. Other key factors that can change the intensity of SERRS include the resonance excitation wavelength, oscillator strength of the electronic excited state, metal-molecule binding site and structure of the substrate cluster. Hence, the optical properties of complexes can be tuned by varying these factors.