Stabilized photoanodes for water oxidation by integration of organic dyes, water oxidation catalysts, and electron-transfer mediators.

Stabilized photoanodes for light-driven water oxidation have been prepared on nanoparticle core/shell electrodes with surface-stabilized donor-acceptor chromophores, a water oxidation catalyst, and an electron-transfer mediator. For the electrode, fluorine-doped tin oxide FTO|SnO2/TiO2|-Org1-|1.1 nm Al2O3|-RuP2+-WOC (water oxidation catalyst) with Org1 (1-cyano-2-(4-(diphenylamino)phenyl)vinyl)phosphonic acid), the mediator RuP2+ ([Ru(4,4-(PO3H2)2-2,2-bipyridine)(2,2-bipyridine)2]2+), and the WOC, Ru(bda)(py(CH2)(3or10)P(O3H)2)2 (bda is 2,2-bipyridine-6,6-dicarboxylate with x = 3 or 10), solar excitation resulted in photocurrents of ∼500 µA/cm2 and quantitative O2 evolution at pH 4.65. Related results were obtained for other Ru(II) polypyridyl mediators. For the organic dye PP (5-(4-(dihydroxyphosphoryl)phenyl)-10,15,20-Tris(mesityl)porphyrin), solar water oxidation occurred with a driving force near 0 V.