title: Understanding Intrinsic Light Absorption Properties of UiO-66 Frameworks: A Combined Theoretical and Experimental Study.
abstract: A combined theoretical and experimental study is performed in order to elucidate the effects of linker functional groups on the photoabsorption properties of UiO-66-X materials. This study, in which both mono- and difunctionalized linkers (with X = OH, NH2, or SH) are investigated, aims to obtain a more complete picture of the choice of functionalization. Static time-dependent density functional theory calculations combined with molecular dynamics simulations are performed on the linkers, and the results are compared to experimental UV/vis spectra in order to understand the electronic effects governing the absorption spectra. The disubstituted linkers show larger shifts than the monosubstituted variants, making them promising candidates for further study as photocatalysts. Next, the interaction between the linker and the inorganic part of the framework is theoretically investigated using a cluster model. The proposed ligand-to-metal-charge transfer is theoretically observed and is influenced by the differences in functionalization. Finally, the computed electronic properties of the periodic UiO-66 materials reveal that the band gap can be altered by linker functionalization and ranges from 4.0 down to 2.2 eV. Study of the periodic density of states allows the band gap modulations of the framework to be explained in terms of a functionalization-induced band in the band gap of the original UiO-66 host.
authors.affiliation: Department of Inorganic and Physical Chemistry, Center for Ordered Materials, Organometallics and Catalysis (COMOC), Ghent University , Krijgslaan 281 (S3), 9000 Ghent, Belgium.|Center for Molecular Modeling (CMM), Ghent University , Technologiepark 903, 9052 Zwijnaarde, Belgium.
authors.forename: Kevin
authors.initials: K
authors.lastname: Hendrickx
authors.affiliation: Center for Molecular Modeling (CMM), Ghent University , Technologiepark 903, 9052 Zwijnaarde, Belgium.
authors.forename: Danny E P
authors.initials: DE
authors.lastname: Vanpoucke
authors.affiliation: Department of Inorganic and Physical Chemistry, Center for Ordered Materials, Organometallics and Catalysis (COMOC), Ghent University , Krijgslaan 281 (S3), 9000 Ghent, Belgium.
authors.forename: Karen
authors.initials: K
authors.lastname: Leus
authors.affiliation: Center for Molecular Modeling (CMM), Ghent University , Technologiepark 903, 9052 Zwijnaarde, Belgium.
authors.forename: Kurt
authors.initials: K
authors.lastname: Lejaeghere
authors.affiliation: Center for Molecular Modeling (CMM), Ghent University , Technologiepark 903, 9052 Zwijnaarde, Belgium.
authors.forename: Andy
authors.initials: A
authors.lastname: Van Yperen-De Deyne
authors.affiliation: Center for Molecular Modeling (CMM), Ghent University , Technologiepark 903, 9052 Zwijnaarde, Belgium.
authors.forename: Veronique
authors.initials: V
authors.lastname: Van Speybroeck
authors.affiliation: Department of Inorganic and Physical Chemistry, Center for Ordered Materials, Organometallics and Catalysis (COMOC), Ghent University , Krijgslaan 281 (S3), 9000 Ghent, Belgium.
authors.forename: Pascal
authors.initials: P
authors.lastname: Van Der Voort
authors.affiliation: Center for Molecular Modeling (CMM), Ghent University , Technologiepark 903, 9052 Zwijnaarde, Belgium.
authors.forename: Karen
authors.initials: K
authors.lastname: Hemelsoet