Fluorescence emission of phenosafranin dye was quenched when this dye was adsorbed on TiO2 particles. Diffuse reflectance laser flash photolysis measurements have shown transient absorption corresponding to the cation radical of phenosafranin when the dye adsorbed on TiO2 was excited with a 532 nm laser pulse. The process of charge injection into TiO2 particles was further confirmed by comparing the results of the diffuse reflectance and emission experiments with those from the dye-coated silica particles. Dependence of relative efficiency of charge injection on the surface coverage of the dye has also been elucidated.
The research described herein was supported by the Office of Basic Energy Sciences of the Department of Energy. This is Document No. NDRL-3073 from the Notre Dame Radiation Laboratory.
