Recent development towards the novel applications and future prospects for cellulose-metal organic framework hybrid materials: a review

The hybrid material created by combining cellulose and MOF is highly promising and possesses a wide range of useful properties. Cellulose-based metal-organic frameworks (CelloMOFs) combine the inherent biocompatibility and sustainability of cellulose with the tunable porosity and diverse metal coordination chemistry of MOFs. Cellulose-MOF hybrids have countless applications in various fields, such as energy storage, water treatment, air filtration, gas adsorption, catalysis, and biomedicine. They are particularly remarkable as adsorbents that can eliminate pollutants from wastewater, including metals, oils, dyes, antibiotics, and drugs, and act as catalysts for oxidation and reduction reactions. Furthermore, they are highly efficient air filters, able to remove carbon dioxide, particulate matter, and volatile organic compounds. When it comes to energy storage, these hybrids have demonstrated exceptional results. They are also highly versatile in the realm of biomedicine, with applications such as antibacterial and drug delivery. This article provides an in-depth look at the fabrication methods, advanced applications of cellulose-MOF hybrids, and existing and future challenges.

Copper single-site engineering in MOF-808 membranes for improved water treatment

MOF-808, a metal-organic framework containing Zr6O8 clusters, can serve as a secure anchoring point for stabilizing copper single-sites with redox activity, thus making it a promising candidate for catalytic applications. In this study, we target the incorporation of Cu-MOF-808 into a mixed-matrix membrane for the degradation of tyrosol, an emerging endocrine-disrupting compound commonly found in water sources, through Fenton reactions, developing innovative technologies for water treatment. We successfully demonstrate the effectiveness of this approach by preparing catalytic membranes with minimal metal leaching, which is one of the primary challenges in developing copper-based Fenton heterogeneous catalysts. Furthermore, we utilized advanced synchrotron characterization techniques, combining X-ray absorption spectroscopy and pair distribution function analysis of X-ray total scattering, to provide evidence of the atomic structure of the catalytic copper sites within the membranes. Additionally, we observed the presence of weak interactions between the MOF-808 and the organic polymer, potentially explaining their enhanced stability.

Polymeric membranes functionalized with nanomaterials (MP@NMs): A review of advances in pesticide removal

The excessive contamination of drinking water sources by pesticides has a pernicious impact on human health and the environment since only 0.1% of pesticides is utilized effectively to control the and the rest is deposited in the environment. Filtration by polymeric membranes has become a promising technique to deal with this problem; however, the scientific community, in the need to find better pesticide retention results, has begun to meddle in the functionalization of polymeric membranes. Given the great variety of membrane, polymer, and nanomaterial synthesis methods present in the market, the possibilities of obtaining membranes that adjust to different variables and characteristics related to a certain pesticide are relatively extensive, so it is expected that this technology will represent one of the main pesticide removal strategies in the future. In this direction, this review focused on, - the main characteristics of the nanomaterials and their impact on pristine polymeric membranes; - the removal performance of functionalized membranes; and - the main mechanisms by which membranes can retain pesticides. Based on these insights, the functionalized polymeric membranes can be considered as a promising technology in the removal of pesticides since the removal performance of this technology against pesticide showed a significant increase. Obtaining membranes that adjust to different variables and characteristics related to a certain pesticide are relatively extensive, so it is expected that functionalized membrane technology will represent one of the main pesticide removal strategies in the future.

Controllable Synthesis of Metal-Organic Framework/Polyethersulfone Composites

Composite materials that contain metal-organic frameworks (MOFs) as a filler and a polymer matrix have attracted attention because they present a combination of high porosity and structural integrity. Phase compatibilities of the MOF and polymer play a vital role in the formation of the composites. In particular, the stiff polymer cannot easily adapt to penetrate into the surface pore of MOF and mainly depends on chemical attractions to form the MOF/polymer composites. We report the synthesis of MOF/polyethersulfone (Young’s modulus = ~2.6 GPa) via different fabrication methods, different MOF types and particle sizes, and different solvents. The formed network structures are robust, monolithic composites with 60% MOF loadings; also, the MOF surface area and porosity were fully preserved. The study explored the formation of the composite between MOF and a stiff polymer and encourages the design of more MOF/polymer composite materials across a wide range of applications.

Metal organic frameworks as solid catalysts for liquid-phase continuous flow reactions

This Feature Article describes the recent developments in the use of MOFs as catalysts under continuous flow conditions illustrating that these materials can meet the required stability.

Well-Defined Cu2 O/Cu3 (BTC)2 Sponge Architecture as Efficient Phenolics Scavenger: Synchronous Etching and Reduction of MOFs in confined-pH NH3 ⋅H2 O

Fabrication of low-dimensional nano-MOFs as well as nanoparticles/metal-organic frameworks (MOFs) hybrids has sparked new scientific interests but remains a challenging task. Taking Cu₃ (BTC)₂ as a proof of concept, it is demonstrated thats NH₃ ⋅H₂ O solution of a confined pH value can readily shape the bulk Cu₃ (BTC)₂ into nanoscale Cu₃ (BTC)₂ , beyond the need to control the crystal growth kinetics of MOFs. Adjusting the pH of NH₃ ⋅H₂ O within a much small range (10-11) allows fine tuning over the size and shape of nanoscale Cu₃ (BTC)₂ . Particularly at pH = 11, NH₃ ⋅H₂ O exhibits weak reducibility that triggers a reduction of part of Cu₃ (BTC)₂ into Cu₂ O, while shaping the other into Cu₃ (BTC)₂ nanowires. Benefiting from the coincidence of reduction and etching effects, the newly generated Cu₂ O dots can in situ anchor onto adjacent Cu₃ (BTC)₂ nanowires at highly dispersive state, forming a well-defined sponge-like architecture built of Cu₂ O dots and nano-Cu₃ (BTC)₂ . The CuO_x derived from annealing of the Cu₂ O dots/nano-Cu₃ (BTC)₂ hybrid preserves the sophisticated sponge architecture and high porosity, and exhibits promising applications in phenol scavenging, with efficiency outperforming its counterparts and many other Cu-based catalysts reported in literature. It is anticipated that the findings here pave the way for the rational design of intricate nano-MOFs in a more efficient way.