Electronic origins of photocatalytic activity in d0 metal organic frameworks

• DOI: 10.1038/srep23676
• Publication Date: 2016-03-29T13:58:58Z
• Authors: Maxim A. Nasalevich; Christopher H. He...; Jara G. Santaclara; Katrine Svane; Bart van der Linden; Sergey L. Veber; Matvey V. Fedin; Arjan J. Houtepen; Monique A. van de...; Freek Kapteijn; Aron Walsh; Jorge Gascon
• Keywords: Photoexcitation; Orbital overlap; HOMO/LUMO

Abstract Metal-organic frameworks (MOFs) containing d 0 metals such as NH 2 -MIL-125(Ti), -UiO-66(Zr) and -UiO-66(Hf) are among the most studied MOFs for photocatalytic applications. Despite structural similarities, we demonstrate that electronic properties of these markedly different. As revealed by quantum chemistry, EPR measurements transient absorption spectroscopy, highest occupied lowest unoccupied orbitals -MIL-125(Ti) promote a long lived ligand-to-metal charge transfer upon photoexcitation, making this material suitable In contrast, in case UiO materials, -orbitals Zr Hf, too low binding energy thus cannot overlap with π* orbital ligand, both frontier localized at organic linker. This reconfiguration results short exciton lifetimes diminishes performance. These highlight importance contributions band edges delineate future directions development photo-active hybrid solids.