Supramolecular Artificial Photosynthesis

The conversion of light energy into chemical fuels by artificial means is a challenging goal of modern science, of great potential impact on long-term energy and environmental problems. As such, Artificial Photosynthesis is one of the most active research areas in applied photochemistry. In this tutorial review the basic ingredients of a biomimetic, supramolecular approach to Artificial Photosynthesis are outlined. First, a brief summary of the relevant structural-functional aspects of natural photosynthesis is provided, as a guide to plausible artificial architectures. Then, candidate energy converting reactions are examined, focusing attention on water splitting. The main functional units of an artificial photosynthetic system are dealt with in some detail, namely, charge separation systems, light harvesting antenna systems, water oxidation catalysts, and hydrogen evolving catalysts. For each type of system, design principles and mechanistic aspects are highlighted with specifically selected examples. Some attempts at integrating the various units into light-to-fuels converting devices are finally discussed. Throughout the review, the emphasis is on systems of molecular and supramolecular nature.