Investigating Light-Induced Processes in Covalent Dye-Catalyst Assemblies for Hydrogen Production

Catalysts

Michele Pavone¹  AnaB. Muñoz-García²  Benjamin Dietzek³  Tatiana Straistari⁴  Sebastian Bold⁴  Vincent Artero⁴  Murielle Chavarot-Kerlidou⁴ 

[1] Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte Sant’Angelo Via Cintia, 80126 Naples, Italy;Department of Physics “Ettore Pancini”, University of Naples Federico II, Complesso Universitario Monte Sant’Angelo Via Cintia, 80126 Naples, Italy;Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany;Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, CNRS, CEA IRIG, 17 rue des Martyrs, F-38000 Grenoble, France;

关键词: solar energy conversion;    push-pull dye;    intersystem crossing;   

DOI  :  10.3390/catal10111340

来源: DOAJ

【 摘 要 】

The light-induced processes occurring in two dye-catalyst assemblies for light-driven hydrogen production were investigated by ultrafast transient absorption spectroscopy. These dyads consist of a push-pull organic dye based on a cyclopenta[1,2-b:5,4-b’]dithiophene (CPDT) bridge, covalently linked to two different H₂-evolving cobalt catalysts. Whatever the nature of the latter, photoinduced intramolecular electron transfer from the excited state of the dye to the catalytic center was never observed. Instead, and in sharp contrast to the reference dye, a fast intersystem crossing (ISC) populates a long-lived triplet excited state, which in turn non-radiatively decays to the ground state. This study thus shows how the interplay of different structures in a dye-catalyst assembly can lead to unexpected excited state behavior and might open up new possibilities in the area of organic triplet sensitizers. More importantly, a reductive quenching mechanism with an external electron donor must be considered to drive hydrogen production with these dye-catalyst assemblies.

【 授权许可】

Unknown