Artificial Photosynthetic Systems Based on [FeFe]-Hydrogenase Mimics: the Road to High Efficiency for Light-Driven Hydrogen Evolution

Hydrogen (H-2) has the potential to replace fossil fuels as the clean energy carrier of the future, particularly if it is produced by water splitting using visible light. Natural [FeFe]-hydrogenase ([FeFei-H(2)ase) is known to catalyze the reversible reduction of protons to H-2 with remarkable activity under mild conditions. In this respect, artificial photosynthetic systems for H-2 production by using sunlight and [FeFd-H(2)ase mimics have attracted much attention, and great progress has been made in recent years. This perspective paper describes our efforts to achieve H-2 evolution by [FeFd-H(2)ase mimics powered by a photosensitizer (PS). Covalent-linked molecular dyads and a triad, a self-assembled micelle system and a robust, inexpensive, nanocrystal CdTe system will be highlighted.