Coadsorption of Cationic Dyes with Surfactants on Colloidal TiO_2 Particles to Achieve Photosensitization in Highly Acidic Media
Absorption and emission characteristics of rhodamine B (RB) were investigated in aqueous solutions of sodium dodecylbenzenesulfonate (DBS) at pH 0.9 in the absence and presence of colloidal TiO<SUB>2</SUB>. From the spectral changes one can obtain detailed information about the interaction between RB, DBS and TiO<SUB>2</SUB>. No adsorption of RB onto the surface of TiO<SUB>2</SUB> occurred at the quite low pH due to the strong electrostatic repulsion between RB molecules and the positively charged TiO<SUB>2</SUB> particles. Addition of DBS was found to be capable of improving the coadsorption of RB onto the surface of TiO<SUB>2</SUB> particles, and thus realizing and efficient charge injection from the excited state of RB into the conduction band of TiO<SUB>2</SUB>.
- Chemistry letters
Chemistry letters 1997(8), 791-792, 1997-08
The Chemical Society of Japan