Delayed electron-hole pair recombination in iron(III)-oxo metal-organic frameworks.

The photodynamic properties of a series of Fe(III)-MOFs have been examined via redox reactions with N,N,N',N'-tetramethyl-p-phenylenediamine as an electron donor and methyl viologen as an electron acceptor. Furthermore, photogeneration of long-lived species in MIL-88B(Fe) has been proven via transient absorption spectroscopy.

Iron(III)-based metal-organic frameworks as visible light photocatalysts.

Herein, a new group of visible light photocatalysts is described. Iron(III) oxides could be promising visible light photocatalysts because of their small band gap enabling visible light excitation. However, the high electron-hole recombination rate limits the yield of highly oxidizing species. This can be overcome by reducing the particle dimensions. In this study, metal-organic frameworks (MOFs), containing Fe3-µ3-oxo clusters, are proposed as visible light photocatalysts. Their photocatalytic performance is tested and proven via the degradation of Rhodamine 6G in aqueous solution. For the first time, the remarkable photocatalytic efficiency of such Fe(III)-based MOFs under visible light illumination (350 up to 850 nm) is shown.

Photocatalytic growth of dendritic silver nanostructures as SERS substrates.

We report a one-step photocatalytic synthesis method of dendritic silver nanostructures. These self-organised structures show an excellent Raman enhancement enabling the detection of analytes from dilute solutions by surface-enhanced Raman spectroscopy.

p-Xylene-selective metal-organic frameworks: a case of topology-directed selectivity.

Para-disubstituted alkylaromatics such as p-xylene are preferentially adsorbed from an isomer mixture on three isostructural metal-organic frameworks: MIL-125(Ti) ([Ti(8)O(8)(OH)(4)(BDC)(6)]), MIL-125(Ti)-NH(2) ([Ti(8)O(8)(OH)(4)(BDC-NH(2))(6)]), and CAU-1(Al)-NH(2) ([Al(8)(OH)(4)(OCH(3))(8)(BDC-NH(2))(6)]) (BDC = 1,4-benzenedicarboxylate). Their unique structure contains octahedral cages, which can separate molecules on the basis of differences in packing and interaction with the pore walls, as well as smaller tetrahedral cages, which are capable of separating molecules by molecular sieving. These experimental data are in line with predictions by molecular simulations. Additional adsorption and microcalorimetric experiments provide insight in the complementary role of the two cage types in providing the para selectivity.