Anthraquinone removal by a metal-organic framework/polyvinyl alcohol cryogel-immobilized laccase: effect and mechanism exploration

The laccase enzyme was successfully immobilized over a magnetic amino-functionalized metal–organic framework Fe3O4-NH2@MIL-101(Cr). Different techniques were used for the characterization of the synthesized materials. The Fe3O4-NH2@MIL-101(Cr) laccase showed excellent resistance to high temperatures and low pH levels with a high immobilization capacity and large activity recovery, due to the combination of covalent binding and adsorption advantages. The long-term storage of immobilized laccase for 28 days indicated a retention of 88% of its initial activity, due to the high stability of the immobilized system. Furthermore, a residual activity of 49% was observed at 85 °C. The immobilized laccase was effectively used for the biodegradation of Reactive Black 5 (RB) and Alizarin Red S (AR) dyes in water. The factors affecting the RB and AR degradation using the immobilized laccase (dye concentration, temperature and pH) were investigated to determine the optimum treatment conditions. The optimum conditions for dye removal were a 5 mg/L dye concentration, temperature of 25 °C, and a pH of 4. At the optimum conditions, the biodegradation and sorption-synergistic mechanism of the Fe3O4-NH2@MIL-101(Cr) laccase system caused the total removal of AR and 81% of the RB. Interestingly, the reusability study of this immobilized enzyme up to five cycles indicated the ability to reuse it several times for water treatment.

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Multifunctional metal–organic framework heterostructures for enhanced cancer therapy

Chemical Society Reviews ◽

10.1039/d0cs00178c ◽

2021 ◽

Author(s):

Jintong Liu ◽

Jing Huang ◽

Lei Zhang ◽

Jianping Lei

Keyword(s):

Cancer Therapy ◽

General Principle ◽

Biomedical Applications ◽

Metal Organic Framework ◽

Metal Organic ◽

Functional Modulation ◽

Organic Framework

We review the general principle of the design and functional modulation of nanoscaled MOF heterostructures, and biomedical applications in enhanced therapy.

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Magnetic Ordering via Itinerant Ferromagnetism in a Metal-Organic Framework

10.26434/chemrxiv.12330866 ◽

2020 ◽

Author(s):

Jesse Park ◽

Brianna Collins ◽

Lucy Darago ◽

Tomce Runcevski ◽

Michael Aubrey ◽

...

Keyword(s):

Charge Transport ◽

Magnetic Order ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Magnetic Ordering ◽

Double Exchange ◽

Itinerant Ferromagnetism ◽

Organic Solids ◽

Metal Organic ◽

Organic Framework

Materials that combine magnetic order with other desirable physical attributes offer to revolutionize our energy landscape. Indeed, such materials could find transformative applications in spintronics, quantum sensing, low-density magnets, and gas separations. As a result, efforts to design multifunctional magnetic materials have recently moved beyond traditional solid-state materials to metal–organic solids. Among these, metal–organic frameworks in particular bear structures that offer intrinsic porosity, vast chemical and structural programmability, and tunability of electronic properties. Nevertheless, magnetic order within metal–organic frameworks has generally been limited to low temperatures, owing largely to challenges in creating strong magnetic exchange in extended metal–organic solids. Here, we employ the phenomenon of itinerant ferromagnetism to realize magnetic ordering at TC = 225 K in a mixed-valence chromium(II/III) triazolate compound, representing the highest ferromagnetic ordering temperature yet observed in a metal–organic framework. The itinerant ferromagnetism is shown to proceed via a double-exchange mechanism, the first such observation in any metal–organic material. Critically, this mechanism results in variable-temperature conductivity with barrierless charge transport below TC and a large negative magnetoresistance of 23% at 5 K. These observations suggest applications for double-exchange-based coordination solids in the emergent fields of magnetoelectrics and spintronics. Taken together, the insights gleaned from these results are expected to provide a blueprint for the design and synthesis of porous materials with synergistic high-temperature magnetic and charge transport properties.

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Solvent-Free Powder Synthesis and MOF-CVD Thin Films of the Mesoporous Metal-Organic Framework MAF-6

10.26434/chemrxiv.9860891.v1 ◽

2019 ◽

Author(s):

Timothée Stassin ◽

Ivo Stassen ◽

Joao Marreiros ◽

Alexander John Cruz ◽

Rhea Verbeke ◽

...

Keyword(s):

Vapor Phase ◽

Metal Organic Framework ◽

Chemical Vapor ◽

Uptake Capacity ◽

Powder Synthesis ◽

Crystalline Films ◽

Metal Organic ◽

Mesoporous Metal ◽

First Time ◽

Organic Framework

A simple solvent- and catalyst-free method is presented for the synthesis of the mesoporous metal-organic framework (MOF) MAF-6 (RHO-Zn(eIm)2) based on the reaction of ZnO with 2-ethylimidazole vapor at temperatures ≤ 100 °C. By translating this method to a chemical vapor deposition (CVD) protocol, mesoporous crystalline films could be deposited for the first time entirely from the vapor phase. A combination of PALS and Kr physisorption measurements confirmed the porosity of these MOF-CVD films and the size of the MAF-6 supercages (diam. ~2 nm), in close agreement with powder data and calculations. MAF-6 powders and films were further characterized by XRD, TGA, SEM, FTIR, PDF and EXAFS. The exceptional uptake capacity of the mesoporous MAF-6 in comparison to the microporous ZIF-8 is demonstrated by vapor-phase loading of a molecule larger than the ZIF-8 windows.

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Faculty Opinions recommendation of High H2 adsorption in a microporous metal-organic framework with open metal sites.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1027708.334689 ◽

2005 ◽

Author(s):

Jon Zubieta

Keyword(s):

Metal Organic Framework ◽

H2 Adsorption ◽

Open Metal Sites ◽

Metal Organic ◽

Organic Framework

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Spherical Sandwich Pt/Au@Pd@UIO-67@UIO-N (N = 66, 67, 69) Core–Shell Catalysts: Zr-Based Metal–Organic Framework Effectively Regulating the Reverse Water–Gas Shift Reaction

SSRN Electronic Journal ◽

10.2139/ssrn.3257349 ◽

2018 ◽

Author(s):

Haitao Xu ◽

Xikuo Luo ◽

Jiajia Wang ◽

Yuqun Yuqun Su ◽

Yansong Li ◽

...

Keyword(s):

Metal Organic Framework ◽

Water Gas Shift ◽

Core Shell ◽

Water Gas Shift Reaction ◽

Reverse Water Gas Shift ◽

Metal Organic ◽

Shift Reaction ◽

Water Gas ◽

Organic Framework

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An Overview of Metal-organic Frameworks-based Acid/Base Catalysts for Biofuel Synthesis

Current Organic Chemistry ◽

10.2174/1385272824999200726230556 ◽

2020 ◽

Vol 24 (16) ◽

pp. 1876-1891

Author(s):

Qiuyun Zhang ◽

Yutao Zhang ◽

Jingsong Cheng ◽

Hu Li ◽

Peihua Ma

Keyword(s):

Alternative Fuels ◽

Heterogeneous Catalysts ◽

Supported Catalysts ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Flexible Structures ◽

Biodiesel Production ◽

Biodiesel Synthesis ◽

Metal Organic ◽

Organic Framework

Biofuel synthesis is of great significance for producing alternative fuels. Among the developed catalytic materials, the metal-organic framework-based hybrids used as acidic, basic, or supported catalysts play major roles in the biodiesel production. This paper presents a timely and comprehensive review of recent developments on the design and preparation of metal-organic frameworks-based catalysts used for biodiesel synthesis from various oil feedstocks, including MILs-based catalysts, ZIFs-based catalysts, UiO-based catalysts, Cu-BTC-based catalysts, and MOFs-derived porous catalysts. Due to their unique and flexible structures, excellent thermal and hydrothermal stability, and tunable host-guest interactions, as compared with other heterogeneous catalysts, metal-organic framework-based catalysts have good opportunities for application in the production of biodiesel at industrial scale.

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Synthesis and Structure of a Clathrated Two-Dimensional Metal-Organic Framework: [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2·H2O (L = Bis(1-pyrazinylethylidene)hydrazine)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20080024 ◽

2008 ◽

Vol 73 (1) ◽

pp. 24-31

Author(s):

Dayu Wu ◽

Genhua Wu ◽

Wei Huang ◽

Zhuqing Wang

Keyword(s):

Metal Organic Framework ◽

Channel Structure ◽

Two Dimensional ◽

X Ray Diffraction ◽

Guest Molecules ◽

X Ray ◽

Square Planar ◽

Metal Organic ◽

Aqueous Meoh ◽

Organic Framework

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.

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