A Comparative Study on Photo-Induced Electron Transfer from Fluorescein to Anthraquinone and Injection into Colloidal TiO2

A dyad—anthraquinone-methyl ester of fluorescein—and its model compound—butyl ester—were synthesized. The effects of photo-induced electron transfer from fluorescein to an organic anthraquinone acceptor and injection into inorganic colloidal TiO2 were studied respectively. It is found that the photo-induced electron transferring to an organic acceptor is much faster than injecting into inorganic colloidal particles when fluorescein was excited by visible light. While inorganic colloidal TiO2 was excited by UV, the electron of fluorescein will inject into TiO2.