Delocalizing Excitation for Highly-Active Organic Photovoltaic Catalysts.
Angew Chem Int Ed Engl
; 63(26): e202402343, 2024 Jun 21.
Article
de En
| MEDLINE
| ID: mdl-38639055
ABSTRACT
Localized excitation in traditional organic photocatalysts typically prevents the generation and extraction of photo-induced free charge carriers, limiting their activity enhancement under illumination. Here, we enhance delocalized photoexcitation of small molecular photovoltaic catalysts by weakening their electron-phonon coupling via rational fluoro-substitution. The optimized 2FBP-4F catalyst we develop here exhibits a minimized Huang-Rhys factor of 0.35 in solution, high dielectric constant and strong crystallization in the solid state. As a result, the energy barrier for exciton dissociation is decreased, and more importantly, polarons are unusually observed in 2FBP-4F nanoparticles (NPs). With the increased hole transfer efficiency and prolonged charge carrier lifetime highly related to enhanced exciton delocalization, the PM6 2FBP-4F heterojunction NPs at varied concentration exhibit much higher optimized photocatalytic activity (207.6-561.8â
mmol h-1 g-1) for hydrogen evolution than the control PM6 BP-4F and PM6 2FBP-6F NPs, as well as other reported photocatalysts under simulated solar light (AM 1.5G, 100â
mW cm-2).
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Langue:
En
Journal:
Angew Chem Int Ed Engl
Année:
2024
Type de document:
Article
Pays d'affiliation:
Chine