State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China.
Chemphyschem. 2013 Jul 22;14(10):2217-24. doi: 10.1002/cphc.201300381. Epub 2013 Jul 3.
Herein, we employ Ag@TiO2 core-shell nanoparticles for surface-enhanced Raman scattering (SERS) investigations of TiO2-N719 dye interfaces. In situ electrochemical SERS investigations of the Ag@TiO2-N719 interaction are systematically carried out under a series of electrode-potential controls. By comparing the potential dependence of resonant and pre-resonant SERS spectra recorded with different laser excitations, bidentate carboxylate linkage is considered to be involved in N719 adsorption on TiO2. Meanwhile, SCN ligand shows obvious interactions with TiO2, and their role in the adsorption and orientation of N719 on TiO2 should not be underestimated. The in situ SERS spectra of Ag@TiO2 show a clear bell-shaped intensity-potential relation for the major bands of N719. A molecule-to-TiO2 charge-transfer resonance is tentatively attributed to account for such a phenomenon. Under the influence of such a charge-transfer resonance, valuable information about the N719-TiO2 interaction as well as the intramolecular deformation of N719 is obtained.
在此，我们采用 Ag@TiO2 核壳纳米粒子对 TiO2-N719 染料界面进行表面增强拉曼散射 (SERS) 研究。通过一系列电极电位控制，系统地进行了 Ag@TiO2-N719 相互作用的原位电化学 SERS 研究。通过比较不同激光激发下记录的共振和预共振 SERS 光谱的电位依赖性，认为双齿羧酸盐键合参与了 N719 在 TiO2 上的吸附。同时，SCN 配体与 TiO2 表现出明显的相互作用，它们在 N719 在 TiO2 上的吸附和取向中的作用不应被低估。Ag@TiO2 的原位 SERS 光谱显示 N719 的主要谱带呈现出清晰的钟形强度-电位关系。暂将分子到 TiO2 的电荷转移共振归因于解释这种现象。在这种电荷转移共振的影响下，获得了有关 N719-TiO2 相互作用以及 N719 分子内变形的有价值信息。
