A Dye Sensitized Photoelectrosynthesis Cell (DSPEC) splits water with visible light using a derivatized, core/shell nanostructured photoanode with the core having a high surface area conductive metal oxide film--such as nanoITO (indium tin oxide) or nanoATO (antimony tin oxide)--coated with a thin outer shell of, for example, TiO.sub.2 formed by Atomic Layer Deposition (ALD). A "chromophore-catalyst assembly" 1, [(PO.sub.3H.sub.2).sub.2bpy).sub.2Ru(4-Mebpy-4-bimpy)Ru(tpy)(OH.sub.2)].s- up.4+, which combines both light absorber and water oxidation catalyst in a single molecule, is attached to the TiO.sub.2 shell. Visible photolysis of the resulting core/shell/assembly structure with a Pt cathode results in water splitting into hydrogen and oxygen.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under Grant Nos. DE-SC0001011 and DE-FG26-08NT01925 awarded by the Department of Energy. The U.S. government has certain rights in the invention.