Fotosintesi artificiale: complessi molecolari di Cobalto come catalizzatori per l’ossidazione dell’acqua

Water oxidation still represents the bottleneck of artificial photosynthesis, that is light driven water splitting into hydrogen and oxygen. This work is focused on the investigation of molecular catalysts based on Cobalt, using a photoactivated system based on S2O82- as the sacrifical oxidant and Ru(bpy)32+ as the photosynthetizer. The advantage in using such species, stems from the abundance of Cobalt on Earth, its limited cost and its promising catalytic activity. This study analyses catalytic Oxygen production by several Cobalt based molecular species with totally inorganic ligands taken from the polyoxometalate pool, and other polinuclear complexes with organic ligands with different coordination geometries of the metal centres. Moreover, the activity of the hexaaquoion Co(H2O)62+ in the presence of different organic ligands added in situ was hexamined, with the aim of getting informations of the reaction mechanism.