Time-Resolved Spectroscopy and High Efficiency Light-driven Hydrogen Evolution of a {Mo 3 S 4 }-Containing Polyoxometalate-Based System
Résumé
Polyoxothiometalate ions are active hydrogen evolution reaction (HER) catalysts based on modular assembly build from electrophilic clusters {MoSx} and vacant polyoxotungstates. Herein, the dumbbell-like anion {PW11O39)2(Mo3S4(H2O)3(OH))2] 8exhibits very high light-driven HER activity while the active cores {Mo3S4} do not contain any exposed disulphido ligands which were suspected at the origin of the HER activity. Moreover, in the catalyst architecture, the two central {Mo3S4} cores are sandwiched by two bulky {PW11O39} 7subunits that act as oxidant resistant protecting groups and behave as electron-collecting units. A detailed photophysical study was carried out confirming the reductive quenching mechanism of the photosensitizer [Ir(bpy)2(dtbbpy)] + by the sacrificial donor triethanolammine (TEOA) and highlighting the very high rate constant for the electron transfer from the reduced photosensitizer to the Thio-POM catalyst. Such results provide new insight about HER activity of the Thio-POM catalysts.
Domaines
Chimie| Origine | Fichiers produits par l'(les) auteur(s) |
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