Abstract:

Negatively charged tetrasulfophthaloeyanines adsorb strongly on the surface of colloidal TiO2 through electrostatic interaction.In comparison with tetraalkoxy phthalocyanines,the interaction between tetrasulfophthaloeyanine and colloid TiO2 was probed by absorption and fluorometric spectroscopy and the apparent association constants K were calculated.Quenching of tetrasulfophthaloeyanine fluorescence by colloidal TiO2 is attributed to the charge injection from the excited singlet stste of tetrasulfophthaloeyanine to the conduction band of TiO2.The photoinduced electron transfer process was further elucidated by fluorescence lifetime measurements using single-photon counting technique.Tetrasulfopthalocyanines were adsorbed on the surface of nanocrystalline TiO2 electrode and their photoelectric properties were measured.It is indicated that the photoelectric response is closely related to the extent of association of tetrasulfophthalocyanines on the TiO2 electrode surface.

Key words: Tetrasulfophthalocyanine, Colloidal TiO₂, Electron transfer reaction