A new approach is described for the preparation of water oxidation photoanodes in a Dye-Sensitized Photoelectrosynthesis Cell (DSPEC) for water splitting. It is based on a chromophore (C) – catalyst (Cat) assembly prepared by a self-assembled bilayer (SAB) on a mesoporous SnO2/TiO2 core/shell electrode, FTO|SnO2/TiO2|-C-Cat. A key feature in the resulting assembly is the in-situ “synthesis” by utilization of non-covalent interactions between long alkyl substituents of the chromophore and catalyst components. The photoanode carries out photoelectrochemical water oxidation for more than 3 hours with ~ 86% faradaic efficiency for oxygen generation. At pH 7 under 1 sun illumination, the photoanode reaches a photocurrent density of ~2.2 mA/cm2 with an incident photon to current efficiency (IPCE) of 29% at 450 nm. With an injection yield of only ~42%, the efficiency of the cell, excluding the losses at the core/shell interface, is a remarkable 67%.
Wang, D.; Wang, L.; Brady, M. D.; Dares, C. J.; Meyer, G. J.; Meyer, T. J.; Concepcion, J. J. A Self-Assembled Chromophore/Catalyst Bilayer for Water Oxidation in a Dye-Sensitized Photoelectrosynthesis Cell J. Phys. Chem. C 2019, 123 (50), 30039-30045. http://dx.doi.org/10.1021/acs.jpcc.9b07125