Biomimetic routes for photosplitting of water

Natural photosynthesis involves splitting of water into O2and H2by thermodynamically uphill electron transfer using photon energy absorbed by green chlorophylls and other light-absorbing molecules in leaf chloroplast. It is a multiphotonmultielectron-photosensitized reaction. The artificial photocatalytic system must mimic both the function and the scheme of natural photosynthesis, to bring about this uphill electron transfer. The key concept is organization to prevent back electron transfer. A preliminary report of the attempts made in our laboratory to promote vectorial electron transfer by using various techniques such as PEC cells and liposomes, using chlorophylls isolated from spinach leaves as well as synthesis of their analogues porphyrins synthesized in the laboratory is presented.