高等学校化学学报

高等学校化学学报 ›› 2011, Vol. 32 ›› Issue (8): 1865.

• 研究论文 • 上一篇    下一篇

Au@TiO2核壳纳米粒子光催化过程的表面增强拉曼光谱研究

刘伟,  郭清华,  秦维,  姚建林, 顾仁敖   

  1. 苏州大学材料与化学化工学部, 苏州 215123
  • 收稿日期:2010-09-02 修回日期:2010-11-22 出版日期:2011-08-10 发布日期:2011-07-19
  • 通讯作者: 姚建林 E-mail:jlyao@suda.edu.cn
  • 基金资助:

    国家自然科学基金(批准号: 20973120, 21073128)和江苏省自然科学基金(批准号: BK2005032)资助.

In-situ Surface Enhanced Raman Spectroscopic Investigation of Photocatalysis at Au@TiO2 Surface

LIU Wei, GUO Qing-Hua, QIN Wei, YAO Jian-Lin*, GU Ren-Ao   

  1. College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
  • Received:2010-09-02 Revised:2010-11-22 Online:2011-08-10 Published:2011-07-19
  • Contact: YAO Jian-Lin E-mail:jlyao@suda.edu.cn
  • Supported by:

    国家自然科学基金(批准号: 20973120, 21073128)和江苏省自然科学基金(批准号: BK2005032)资助.

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被引次数

10

摘要： 利用聚电解质的静电吸附作用（层层组装）,在Au纳米粒子表面包裹上不同层数的二氧化钛前驱体TALH，通过退火形成Au@TiO2复合纳米粒子.以苯硫酚（TP）作为探针分子对退火前复合纳米粒子不同壳层厚度的SERS效应进行表征；可以发现：SERS信号强度的变化跟壳层厚度密切相关，当Au表面包裹至三层TALH时，信号几乎完全消失.此外，结合紫外照射，利用SERS对亚甲基蓝在TiO2壳层表面的光催化降解过程进行现场研究.结果表明：MB的降解主要经历了从多体及二聚体吸附逐渐向单体吸附方式转变，随后又经历了一个脱甲基的过程.因此，本工作发展了将一种紫外催化与现场SERS检测相结合的技术，该技术有望发展成为检测光催化过程，研究表面催化机理的一种强有力的工具

关键词: Au@TiO2核壳纳米粒子, 表面增强拉曼光谱, 层层组装技术, 光催化, 机理

Abstract: Based on the polyelectrolyte-mediated electrostatic adsorption (layer by layer method), Au@TiO2 core shell nanoparticles were prepared through the modification of the different layers of TALH on Au nanoparticles followed with a calcination. By using thiophenol as probe, the surface enhanced Raman scattering (SERS) effect was observed from Au nanoparticles attached with the TiO2 precursor. The SERS effect was dependent on the shell thickness. After coated with three layers of TALH, SERS effect from the Au nanoparticles core disappeared. The photocatalytic processes of methylene blue (MB) was investigated on Au@TiO2 by in situ SERS under UV illumination. The observation of C-N-C skeleton deformation vibrational mode at 450 cm-1 and 504 cm-1 indicated that MB adsorbed on the Au@TiO2 surface in a dimmer or polymer formation at the initial stage. With the increase of the UV illumination time, the band at 481cm-1 assigned to the monomer of MB was enhanced and the bands at 1180 cm-1 and 1073 cm-1 assigned to the C-H relevant vibrational modes disappeared. It indicated that the photocatalytic degradation of MB on Au@TiO2 underwent the transformation of dimmer or polymer to the monomer initially, followed with the degradation of methyl group. The in situ SERS technique combined with UV illumination might be developed as one of powerful tools for monitoring the photocatalytic reactions.

Key words: Au@TiO2 core shell nanoparticles, Surface enhanced Raman spectroscopy, Layer-by-layer technique, Photocatalysis, Mechanism

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