Photo–Initiated Electron–Transfer at the Interface between AnataseTiO₂Nanocrystallites and Transition–Metal Polypyridyl Compounds: Recent Advances

Abstract

Molecular control of solar light harvesting and interfacial charge transfer at mesoporous, nanocrystalline semiconductor thin films are described. Light absorption by transition‐metal coordination compounds anchored to wide band‐gap semiconductors can initiate electron‐transfer processes that ultimately reduce the semiconductor and oxidize the coordination compound. Such photo‐induced charge separation is a key step for solar energy conversion. Three different interfacial charge‐separation mechanisms are discussed in addition to regeneration processes wherein a mobile donor donates an electron to the oxidized coordination compound. Inorganic chemistry plays a central role in this approach to solar energy conversion, which may ultimately be optimized for practical applications.