Photo-induced direct interfacial charge transfer at TiO2 modified with hexacyanoferrate(iii)

Abstract

Photo-induced electron-transfer reactions occurring at the interface between titanium dioxide modified with hexacyanoferrate(III) (Fe(III)-CN-TiO₂) were characterized. After the modification of TiO₂ with [Fe(CN)₆]³⁻ ions, a new absorption appeared in the visible light region (410 to 700 nm). Absorption spectroscopy measurements showed that Fe(III)-CN-TiO₂ was converted to Fe(II)-CN-TiO₂ under visible light irradiation (>520 nm), which indicates that the new absorption was assignable to direct charge transfer from the valence band to the modified Fe(III) ions.