Applications for Metal−Organic Frameworks (MOFs) as Quantum Dot Semiconductors

Abstract

The structure of MOF-5 is considered as being constructed of discrete semiconductor Zn 4 O 13 quantum dots stabilized and interconnected by terephthalate linkers. Terephthalate can absorb light and sensitize the semiconductor dots. In this way, MOFs exhibit the photocatalytic activity of MOF-5 for the degradation of phenols. As a photocatalyst, the most remarkable feature of MOF-5 is the observation of reverse shapeselectivity in which large phenolic molecules that cannot access the interior of the micropores are degraded significantly faster than those others that can enter into the particle. MOF-5 also exhibits activity as an active component in photovoltaic and electroluminescence cells.

Metal–Organic Frameworks: Opportunities for Catalysis

“…[67] For 0D MOF structures, polycationic nodes can act as semiconductor quantum dots which can be activated upon photostimuli with the linkers serving as photon antennae. [68,69] Theoretical calculations show that MOFs are semiconductors or insulators with band gaps between 1.0 and 5.5 eV which can be altered by changing the degree of conjugation in the ligands.…”

“…[71] Photo-oxidation examples can be found elsewhere. [66,69,71,72] On the other hand, nanosized TiO 2 [73] and ZnO (1.4 nm) [74] can be hosted in MOF-5 to generate new types of quantum-dot materials. Unfortunately, most of the simulation and experimental studies have been carried out on MOF-5.…”

Origin of highly active metal–organic framework catalysts: defects? Defects!

“…16 In 2007, Corma et al made the acknowledged statement that "the potential of MOFs is largely hampered by the fact that the coordination sphere of the metal ion is usually completely blocked by the organic linkers". 14 One year later, we published in the New Journal of Chemistry a study on the role of defect sites in MOF-5 which are at the origin of its catalytic activity. 17 Since then, a number of striking examples have been reported on their outstanding catalytic activities and selectivity.…”

Thin film nano-photocatalyts with low band gap energy for gas phase degradation of p -xylene: TiO 2 doped Cr, UiO66-NH 2 and LaBO 3 (B = Fe, Mn, and Co)

“…MOFs showed high photocatalytic activity and superiority of MOFs materials are the band gap energy is easily changed by adding substances such as transition metals or organic functional groups like halogen, amine, or alkyl groups, resulting in increased photocatalytic activity of MOFs and the use of solar light becomes more efficient [10,11]. MOF-5 shows photocatalytic activity in the decomposition of phenol [12]. UiO, the water resistance MOF, is used as photocatalyst for the oxidation of water and reduction of CO 2 under irradiation of the light with wavelengths greater than 300 nm [13].…”