Light driven water oxidation is a key step in artificial photosynthesis, aimed at splitting water into hydrogen and oxygen with sunlight. In such process, the interactions between a photosensitizer (PS) and a water oxidation catalyst (WOC) play a crucial role in the rates of photoinduced electron transfers, determining the overall quantum efficiency of the system. In this work, by means of Small Angle X-ray Scattering (SAXS) we investigate the nature of the aggregates between ruthenium polypyridine photosensitizers (Rubpy and Ru4dend) and a tetraruthenium polyoxometalate (Ru4POM) water oxidation catalyst. Aggregate scattering is confirmed by the strong intensity-increase in the low-q regime, whereas the power law-fit of this region show slopes between −3 and −4, suggesting globular and porous aggregates. Intermolecular PS/WOC distances lower than 3 nm support the observed fast photoinduced electron transfers (<120 ps), however the proximity of the two components in the hybrids is also responsible for fast charge recombination. Approaches for inhibiting such undesired process are discussed.
Titolo: | Ruthenium based photosensitizer/catalyst supramolecular architectures in light driven water oxidation | |
Autori: | ||
Data di pubblicazione: | 2017 | |
Stato di pubblicazione: | Pubblicato | |
Rivista: | ||
Abstract: | Light driven water oxidation is a key step in artificial photosynthesis, aimed at splitting water into hydrogen and oxygen with sunlight. In such process, the interactions between a photosensitizer (PS) and a water oxidation catalyst (WOC) play a crucial role in the rates of photoinduced electron transfers, determining the overall quantum efficiency of the system. In this work, by means of Small Angle X-ray Scattering (SAXS) we investigate the nature of the aggregates between ruthenium polypyridine photosensitizers (Rubpy and Ru4dend) and a tetraruthenium polyoxometalate (Ru4POM) water oxidation catalyst. Aggregate scattering is confirmed by the strong intensity-increase in the low-q regime, whereas the power law-fit of this region show slopes between −3 and −4, suggesting globular and porous aggregates. Intermolecular PS/WOC distances lower than 3 nm support the observed fast photoinduced electron transfers (<120 ps), however the proximity of the two components in the hybrids is also responsible for fast charge recombination. Approaches for inhibiting such undesired process are discussed. | |
Handle: | http://hdl.handle.net/11368/2892436 | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/j.ica.2016.04.010 | |
URL: | http://www.sciencedirect.com/science/article/pii/S0020169316301621 | |
Appare nelle tipologie: | 1.1 Articolo in Rivista |
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