Charge-Transfer Effect on Surface-Enhanced Raman Scattering (SERS) in an Ordered Ag NPs/4-Mercaptobenzoic Acid/TiO2 System

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• 作者：Xiaolei Zhang ; Zhi Yu ; Wei Ji ; Huimin Sui ; Qian Cong ; Xu Wang ; Bing Zhao
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：October 1, 2015
• 年：2015
• 卷：119
• 期：39
• 页码：22439-22444
• 全文大小：359K
• ISSN：1932-7455

文摘

With the explosive development of analysis and detection techniques based on surface-enhanced Raman scattering (SERS), the further understanding and exploitation of the chemical mechanism becomes particularly important. We investigated the charge transfer (CT) effect on SERS in a semiconductor鈥搈olecule鈥搈etal system constructed with Ag NPs, 4-mercaptobenzoic acid (MBA) molecule, and atomic level TiO₂. To ensure more ordering, the system is constructed by a layer-by-layer self-assembly method. After introducing TiO₂, we found that the relative band intensity of some peaks displayed a distinct difference, which is attributed to the Herzberg鈥揟eller contribution that occurs via CT. We also proposed a possible mechanism responsible for the selective enhancement observed in the SERS spectra of the Ag NPs/MBA/TiO₂ system. This work will not only provide much deeper insight into the CT mechanism in SERS but also help in the development of a method to construct metal鈥搒emiconductor-based SERS substrates.