Electrochemical redox-potentials were obtained by cyclic voltammetry (CV) using a three-electrode cell and an electrochemistry
workstation (e-corder (ED 401) potentiostat). The dyes sensitized
TiO2films were used as a working electrode. The Ag/AgCl in saturated KCl solution and Pt wire were utilized as reference and
counter electrodes with a scan rate of 50 mV/s.