Raman Spectroscopic Investigation on TiO2-N719 Dye Interfaces Using Ag@TiO2 Nanoparticles and Potential Correlation Strategies

• Published in: Chemphyschem Vol. 14; no. 10; pp. 2217 - 2224
• Main Authors: Qiu, Zhi, Zhang, Meng, Wu, De-Yin, Ding, Song-Yuan, Zuo, Qi-Qi, Huang, Yi-Fan, Shen, Wei, Lin, Xiao-Dong, Tian, Zhong-Qun, Mao, Bing-Wei
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 22.07.2013; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Subjects: Applied sciences; charge transfer; Chemistry; Colloidal state and disperse state; Coloring Agents - chemistry; core-shell nanoparticles; dye-sensitized solar cells; Energy; Exact sciences and technology; General and physical chemistry; Ligands; Nanoparticles; Nanoparticles - chemistry; Natural energy; Organometallic Compounds - chemistry; Particle Size; Photovoltaic conversion; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Raman spectroscopy; Silver - chemistry; Solar cells. Photoelectrochemical cells; Solar energy; Spectrum analysis; Spectrum Analysis, Raman; Surface physical chemistry; Surface Properties; Thiocyanates - chemistry; Titanium - chemistry; titanium dioxide; Dye-sensitized solar cell; Binary compound; Correlation; Dyes; Nanoparticle; Transition element compounds; Raman spectroscopy; dye-sensitized solar cells; core―shell nanoparticles; Coated particle; titanium dioxide; Raman spectrometry; Titanium oxide; Charge transfer; Interface; charge transfer; core-shell nanoparticles
• DOI: 10.1002/cphc.201300381
• ISSN: 1439-4235

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. Surface studies: Ag@TiO2 core–shell nanoparticles enhance the surface Raman signals of N719 dye molecules adsorbed on the TiO2 shell. This allows electrochemical surface‐enhanced Raman spectroscopic investigations of the Ag@TiO2–N719 interface under pre‐resonance conditions. A bell‐shaped intensity–potential relation for the major bands of N719 is observed.