A surface-enhanced FT-Raman spectroscopic method for studying of viologen dye in an electrochromic device

摘要

Surface-enhanced Raman spectroscopy (SERS) has been used to study, in situ, the molecular structure of an electrochromic device composed of a thin nanoporous, nanocrystalline film of anatase titania (TiO_2) derivatised with the viologen l-ethyl-l'-ethylphosphonato-4,4' -bipyridyl dichloride (EPV). Silver colloid solution was added to the surface of the TiO_2 film to provide the SERS activity. Raman spectra of the EPV were obtained as the potential was varied, giving a unique insight into the molecular structural changes giving rise to the electrochromic effect. The presence of the small amount of Ag colloid did not affect the performance of the device. Incorporation of silver particles directly into the TiO_2 layer, instead of adding colloid solution to the surface, was not successful.