PHOTOCHEMICAL REDUCTION OF CARBON DIOXIDE TO FORMATE USING 4,4’-BIPYRIDINIUM AND PYRIDINIUM DERIVATIVES AS ELECTRON TRANSFER MEDIATORS

摘要

The emulation of a photosynthesis system requires two components: photochemical reduction of CO2 and oxidation of water. Polypyridyl ruthenium complexes are attractive compounds for use in artificial photosynthesis because of their ability to transfer energy and electrons in a number of conversion processes. Similar to three component systems for hydrogen production, a CO2 photocycle is comprised of a photosensitizer, a redox mediator for electron transfer and a sacrificial oxidant to regenerate the depleted photosensitizer. Most of the research on solar energy conversion in this type of CO2 photoactivation system has been directed to developing novel sensitizers, but scarcely little to discover new electron relays and redox catalysts.