Visible-Light-Driven Photocatalytic Water Oxidation by a π-Conjugated Donor Acceptor Donor-Chromophore/Catalyst Assembly

The organic chromophore 2,2'-(benzo[c][1,2,5]thiadiazole-4,7-diyObis(thiophene-3-carboxylic acid), T2-BTD, was prepared and investigated along with metal complex [Ru(bda)(pyP)(2)] (bda = 2,2'-bipyridine-6,6'-dicarboxylate; pyP = 3-(pyridine-4-yloxy)propyl)phosphonic acid), RuC, for light-driven water splitting in dye sensitized photoelectrochemical cells. The resulting co-loaded organic chromophore plus catalyst surface assembly was evaluated by photocurrent transient measurement and direct O-2 detection using a collector-generator cell. The complete SnO2/TiO2 core-shell-based photoanode exhibited an enhanced photocurrent (similar to 38 pA cm(-2)) compared to that with only the chromophore pA cm(-2)). A modest Faradaic efficiency of 12% was recorded for O-2 generation under 1 sun illumination in pH 3.9, 0.1 M acetate buffer solutions.