3] 2+(bpy= 2, 2′-bipyridine) as the photosensitizer,[Co4O4 (O2CMe) 4 (py) 4](py= pyridine)
as the molecular catalyst and Na2S2O8 as the sacrificial electron acceptor. The
photochemical quantum yield of the process reaches the outstanding value of 30% and
depends on pH and catalyst concentration. Transient absorption spectroscopy experiments
aimed to clarify the first events of the photocatalytic process are also reported.