Oxygen Evolution from Water via Redox Catalysis

The decomposition of water by sunlight is a fascinating concept in view of today's energy debate. Evolution of O/sub 2/ according to 4Ce/sup 4 +/ + 2H/sub 2/O ..-->.. 4Ce/sup 3 +/ + 4H/sup +/ + O/sub 2/ or 4Ru(bpy)/sub 3//sup 3 +/ + 2H/sub 2/O ..-->.. 4Ru(bpy)/sub 3//sup 2 +/ + 4H/sup +/ + O/sub 2/ could be a first step in this direction. Suitable redox catalysts are P + O/sub 2/ and IrO/sub 2/. Ce/sup 3 +/ and Ru(bpy)/sub 3//sup 2 +/ can be photochemically reoxidized with evolution of H/sub 2/.