The silane-derivatized catalyst, Ru(bda)(L)2 (bda = 2,2′-bipyridine-6,6′-dicarboxylate, L = 4-(6-(triethoxysilyl)hexyl)pyridine), is stabilized on metal oxide electrode surfaces over an extended pH range. It maintains its reactivity on the electrode surface toward electrochemical oxidation over a wide range of conditions. On surfaces of mesoporous nanostructured core/shell SnO2/TiO2, with a TiO2 stabilized inner layer of the Ru(II) polypyridyl chromophore, [Ru(4,4′-(PO3H2)2bpy)(bpy)2]2+ (RuP2+; bpy = 2,2′-bipyridine), highly efficient photoelectrochemical water oxidation catalysis occurs to produce O2 with a maximum efficiency of ∼1.25 mA/cm2. Long-term loss of catalytic activity occurs with time owing to catalyst loss from the electrode surface by axial ligand dissociation in the high oxidation states of the catalyst.
Wu, L.; Eberhart, M.; Nayak, A.; Brennaman, M. K.; Shan, B.; Meyer, T. J. A Molecular Silane-Derivatized Ru(II) Catalyst for Photoelectrochemical Water Oxidation. J. Am. Chem. Soc. 2018, 140 (44), 15062-15069. http://dx.doi.org/10.1021/jacs.8b10132