Sensitive surface-enhanced Raman scattering of TiO2/Ag nanowires induced by photogenerated charge transfer
Sensitive surface-enhanced Raman scattering of TiO2/Ag nanowires induced by photogenerated charge transfer
复制标题
光生电荷转移引起的 TiO2/Ag 纳米线的灵敏表面增强拉曼散射
DOI：
10.1016/j.jcis.2017.08.023
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发表时间：
2017-12-01
影响因子：
9.9
通讯作者：
Wang, Wenzhong
中科院分区：
文献类型：
--
作者：
Zhao, Xin;Zhang, Weiwei;Wang, Wenzhong
在这项工作中，半导体 TiO2 纳米线成功地与等离子体金属银纳米颗粒耦合，制备了具有增强敏感拉曼基底的混合纳米结构。通过检测 R6G 分子的拉曼信号来评估制造的混合纳米结构的 SERS 活性。制备的 TiO2/Ag 纳米线/纳米颗粒混合纳米结构显示出对 R6G 分子的灵敏检测能力。基于Ag纳米颗粒、TiO2纳米线和R6G分子的能带结构，杂化纳米结构增强的灵敏SERS活性归因于有效的电荷转移过程，其中光生电子从金属Ag纳米颗粒转移到TiO2纳米线的导带，然后转移到R6G分子的LUMO能级，从而增强SERS活性。这种高效的电荷转移过程是通过等离子体金属Ag纳米粒子、半导体TiO2纳米线和R6G分子的协同效应实现的。此外，混合纳米结构在可见光（λ > 420 nm）照射下的光响应特性明显证实了光激发电子从金属Ag纳米颗粒到TiO2纳米线导带的转移过程。这项工作取得的结果表明，有效转变等离激元金属纳米粒子/半导体/分子混合纳米结构中的电荷转移可以显着增强其SERS活性。 (C) 2017 Elsevier Inc. 保留所有权利。
In this work, the semiconductor TiO2 nanowires were successfully coupled with plasmonic metal Ag nanoparticles to fabricate hybrid nanostructures with enhanced sensitive Raman substrate. The SERS activities of fabricated hybrid nanostructures were evaluated by detecting the Raman signals of R6G molecules. The fabricated TiO2/Ag nanowire/nanoparticle hybrid nanostructures show sensitive detection ability for R6G molecules. Based on the band structures of Ag nanoparticle, TiO2 nanowire and R6G molecule, the enhanced sensitive SERS activities of hybrid nanostructures is ascribed to an efficient charge transfer process, in which the photogenerated electrons transfer to the conduction band of TiO2 nano wires from metal Ag nanoparticles, and then to LUMO level of R6G molecules, leading to enhanced SERS activities. This efficient charge transfer process is achieved by the synergistic effects of plasmonic metal Ag nanoparticle, semiconductor TiO2 nanowire and R6G molecule. Furthermore, the transfer process of photoexcited electrons from metal Ag nanoparticle to conduction band of TiO2 nanowire is evidently confirmed by the photoresponse properties of hybrid nanostructures under illumination only with visible light (lambda > 420 nm). The findings achieved in this work demonstrate that efficient turning the charge transfer in plasmonic metal nanoparticle/semiconductor/molecule hybrid nanostructure can significantly enhance its SERS activity. (C) 2017 Elsevier Inc. All rights reserved.