Metal-organic frameworks (MOFs) exhibit a huge potential for gas separation. ZIF-8 is an interesting candidate due to its high thermal stability and its pore properties. By liquid phase epitaxy, the growth of the highly oriented surface-anchored MOF ZIF-8 on non-porous and porous surfaces has been proven. The preparation of monolithic ZIF-8 thin films supported by porous a-Al 2 O 3 substrates modified by a thin layer of Au is investigated. The layer-by-layer deposition process accomplished via a dipping procedure results in the formation of defect-or crack-free membranes, preliminary characterized by the determination of ethane and ethene permeance.

High quality, monolithic UiO-66-NH 2 thin films on diverse solid substrates have been prepared via a low temperature liquid phase epitaxy method. The achievement of continuous films with low defect densities and great stability against high temperatures and hot water is proven, clearly outperforming other reported types of MOF thin films.Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) represent a class of highly functional solid materials assembled from metal or metal/oxo nodes and di-or higher-topic organic linkers, [1,2] that continue to receive enormous attention. Due to their modular composition and the ability to access large number of topologies, [3] a huge number of different types of these porous materials, covering a broad spectrum of functionalities, has become available. In addition, combination of different types of Hetero-MOFs fabricated by employing heteroepitaxy via layer-by-layer procedures [4] allows the integration of several different functionalities in these materials, including electrical conductivity, [5] optical upconversion, [6] luminescent properties, and the ability to modulate electrical properties upon illumination with light. [7] For numerous usages of MOFs, the commonly isolated powder-form, consisting of μm-sized particles, is well suited, e. g. for gas storage [8] and water treatment applications. [9]

Background The removal of phenol from aqueous solution via photocatalytic degradation has been recognized as an environmentally friendly technique for generating clean water. The composite nanofibers containing PAN polymer, CNT, and TiO2 NPs were successfully prepared via electrospinning method. The prepared photocatalyst is characterized by SEM, XRD, and Raman spectroscopy. Different parameters are studied such as catalyst amount, the effect of pH, phenol concentration, photodegradation mechanism, flow rate, and stability of the composite nanofiber to evaluate the highest efficiency of the photocatalyst. Results The composite nanofibers showed the highest photodegradation performance for the removal of phenol using UV light within 7 min. The pH has a major effect on the photodegradation of phenol with its maximum performance being at pH 5. Conclusions Given the stability and flexibility of the composite nanofibers, their use in a dynamic filtration is possible and can be even reused after several cycles.

Invited for this month's cover is the group of Dr. Tawheed Hashem from the Karlsruhe Institute of Technology. The cover picture shows a successful synthesis of high quality, monolithic UiO‐66‐NH2 MOF thin films on diverse solid substrates via a low‐temperature liquid phase epitaxy method. The achievement of continuous MOF‐coatings with low defect densities and pronounced stability against high temperatures and hot water was proven. The new type of coatings clearly outperforms other reported types of MOF thin films. Read the full text of their Communication at 10.1002/open.201900324.

In the context of thin film nanotechnologies, metal-organic frameworks (MOFs) are currently intensively explored in the context of both, novel applications and as alternatives to existing materials. When it comes to applications under relatively harsh conditions, in several cases it has been noticed that the stability of MOF thin films deviates from the corresponding standard, powdery form of MOFs. Here, we subjected SURMOFs, surface-anchored MOF thin films, fabricated using layer-by layer methods, to a thorough characterization after exposure to different harsh aqueous environments. The stability of three prototypal SURMOFs, HKUST-1, ZIF-8, and UiO-66-NH2 was systematically investigated in acidic, neutral, and basic environments using X-ray diffraction and electron microscopy. While HKUST-1 films were rather unstable in aqueous media, ZIF-8 SURMOFs were preserved in alkaline environments when exposed for short periods of time, but in apparent contrast to results reported in the literature for the corresponding bulk powders- not stable in neutral and acidic environments. UiO-66-NH2 SURMOFs were found to be stable over a large window of pH values.