Photosensitization of TiO2 semiconductor with porphyrin

Abstract Zn-tetrasulfophenylporphyin (ZnTSPP), stable colloidal TiO 2 and a transparent microporous TiO 2 electrode have been prepared. The interaction of ZnTSPP with colloidal TiO 2 was studied by absorption and fluorescence spectroscopy, the apparent association constant for the association between ZnTSPP and TiO 2 nanoparticles is about 1.6 × 10 4 M −1 . ZnTSPP adsorbed on colloidal TiO 2 can participate in the sensitization process by injecting electrons from its excited states into the conduction band of TiO 2 . Upon excitation of its absorption band, 90% of the fluorescence emission of ZnTSPP could be quenched by colloidal TiO 2 and the maximum of incident photon to current efficiency is 51.3% at 427 nm with a 10 μ m thick TiO 2 film sensitised by ZnTSPP.