Visible light-induced water oxidation catalyzed by molybdenum-based polyoxometalates with mono- and dicobalt(III) cores as oxygen-evolving centers

The Mo-based polyoxometalates containing mono-and dicobalt(III) catalyst cores, [CoMo6O24H6](3-) and [Co2Mo10O38H4](6-), were found to serve as O-2-evolving catalysts in a system consisting of tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)(3)(2+)) and sodium persulfate (S2O82-) in an aqueous borate buffer solution at pH 8.0. Kinetics of O-2 evolution reveals that the higher cobalt nuclearity is not necessary to attain the highly active nature of the catalyst.