Copper-based Metal-organic Framework Research Articles

Over 11 kg m-2 h-1 Evaporation Rate Achieved by Cooling Metal-Organic Framework Foam with Pine Needle-Like Hierarchical Structures to Subambient Temperature.

Solar steam generation has become a hot research topic because of its great potential to alleviate the drinking water crisis without extra energy input. Although some efforts focusing on designing spatial geometry have been made to multiply the evaporation performances of up-to-date three-dimensional evaporators, they still have some shortcomings, such as low material and space utilization efficiencies, complex spatial geometry, energy loss due to the hot solar absorption surface, and salt crystallization due to inefficient water supply. Herein, a biomimetic copper-based metal-organic framework (Cu-Cu(OH)2-MOF) foam sheet with interconnected pores and pine needle-like hierarchical structures consisting of Cu(OH)2 nanowires and MOF nanowhiskers is fabricated. The pine needle-like hierarchical structures of Cu-Cu(OH)2-MOF foam contribute to absorbing solar energy and supplying sufficient water by trapping incident light and enhancing the capillary force, respectively. Inspired by drying clothes outside under solar irradiation, through exposing one end of the Cu-Cu(OH)2-MOF foam to air, the biface evaporator achieves a subambient evaporation surface temperature and an evaporation rate of up to 3.27 kg m-2 h-1 under only one sun illumination. Furthermore, when coupled with an air flow, the biface evaporator realizes an excellent evaporation rate of 11.58 kg m-2 h-1 with an energy efficiency of 160.07% even in seawater, ensuring its great application prospect to be used in drinking water production and seawater desalination.

Effect of amine type on acidic toxic gas adsorption at ambient conditions on modified CuBTC

Two amine-modified copper-based Metal Organic Frameworks (MOF (CuBTC)) of different surface chemical and textural features were synthesized and used as adsorbents of acidic toxic gases (NO2 and H2S) in both moist (71% relative humidity (R.H.)) and dry conditions. The initial and exhausted samples were characterized by nitrogen adsorption, powder X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis and Fourier transform infrared spectroscopy. The addition of melamine prevented full growth of CuBTC crystals and resulted in amorphous-like particles with sizes less than 200 nm. The material was non-porous with a small surface area. When urea was used as an amine source, the resulting particles maintained the overall octahedral shape of the parent CuBTC MOF and the material was more porous than the parent MOF. While the urea-modified CuBTC sample performed well as an NO2 adsorbent in the presence of moisture, the reactivity of the melamine-modified sample and its physical properties provided a favorable environment for the removal of H2S. The incorporation of amines into the MOF structure also resulted in surface defects /open copper sites that favored the removal of toxic gases in dry conditions. The reactivity of the adsorbents with toxic gases was demonstrated by the changes in the adsorbent colors, in texture, and in surface chemistry (organic salts, complexes, sulfides and nitrates were formed).

Influence of HKUST-1 and emeraldine based on the long-term stability of emeraldine salt-coated SP-POF for room temperature optical NH3 gas sensing

A long-term sensitivity performance of conducting polymers and metal-organic frameworks coated on side-polished plastic optical fibre (SP-POF) was presented. SP-POF is an excellent option for potential long-distance and remote gas sensing and monitoring application. The presence of functional groups, porosity and surface area of the active materials were validated by Raman, Fourier transform infrared (FT-IR), X-Ray diffraction (XRD) and BET analyses. The sole copper-based metal-organic framework (HKUST-1)-coated SP-POF exhibited a good sensitivity (0.83/vol%) with a response time of 1.54 min. Further, the influence of acid dopants and oxidants on the optical response of doped-polyaniline (the emeraldine salt, ES) to 1% ammonia (NH3) gas was also optimised. Significant influence of HKUST-1 and emeraldine base (EB) on long-term optical NH3 sensitivity of emeraldine salt (ES)-coated SP-POF were related to NH3 desorption rate and affinity of the materials towards atmospheric vapour. ES-EB composite has exhibited higher NH3 sensitivity to the sole ES and ES-(HKUST-1) with minimal loss of sensitivity to a set of high NH3 gas concentrations over 70 days. ES-EB coated SP-POF has exhibited minimal sensitivity loss to NH3 gas throughout the test duration with a 7.8% decrease followed by ES (28.1%) and ES-(HKUST-1) (50.86%). Development of SP-POF coated with ES-EB composite is a viable approach to retain good optical NH3 sensitivity and stability at room temperature with a relative humidity of ~50%.

Composite of magnetic carbon quantum dot-supported ionic liquid and Cu-BDC (CCDC no. 687690) MOF: A triple catalytic composite for chemical transformations

A novel magnetic triple composite was synthesized through immobilization of DABCO-based ionic liquid on magnetic carbon quantum dot, followed by conjugation of the resultant compound with a copper-based metal-organic framework (CCDC no. 687690). The as-prepared composite was characterized via FESEM/EDS, XRD, TGA, FTIR, VSM and elemental mapping analysis and utilized as a magnetic catalyst for promoting three-component reaction of malononitrile, dimedone and aldehydes under mild reaction condition to furnish etrahydrobenzo[b]pyrans. The catalyst exhibited high catalytic activity and could promote the reaction of various aldehydes with different electronic densities. Moreover, the catalyst could be magnetically collected and successfully reused for five reaction runs with slight loss of the catalytic activity. Notably, comparison of the activity of the catalyst with that of ionic liquid, magnetic carbon quantum dot and metal-organic framework confirmed superior catalytic activity of the former.

Highly selective and sensitive electrochemical determination of cysteine based on complexation with gold nanoparticle-modified copper-based metal organic frameworks.

A gold nanoparticle-modified copper-based metal organic framework (Au NPs@Cu-BDC) was fabricated for the electrochemical determination of cysteine (Cys-SH). The nanocomposites were characterized using different techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), powder X-ray spectroscopy (PXRD), thermogravimetry (TGA), nitrogen adsorption-desorption isotherms, and Fourier transform infrared spectroscopy (FTIR). Formation of a new anodic peak of Cu(II)-Cys complex at + 0.43V was used to detect Cys-SH. Cyclic and square wave voltammetric studies proved that the Au NPs enhanced the conductivity of Cu-BDC. The proposed electrode exhibited a linear range of 0.0015-10.5μM and low detection limit of 0.0004μM with a good sensitivity of 0.78 ± 0.01μA μM. The as-fabricated electrode was successfully used for the estimation of Cys-SH in real samples (human plasma, urine, and saliva) with recovery % of 99-100% and RSD % of 2.7-3.6%, respectively.

Optical and electrochemical dual detection of β-lactoglobulin based on the methylene blue@copper-based metal-organic framework

<italic>β</italic>-lactoglobulin is an effective indicator of allergic protein detection. Herein, we produced a copper-based metal-organic framework coated with methylene blue, to realize the optical and electrochemical dual detection of <italic>β</italic>-lactoglobulin. Methylene blue was successfully encapsulated inside the copper-based metal-organic framework and released after addition of <italic>β</italic>-lactoglobulin. As the concentration of<italic> β</italic>-lactoglobulin increased, the intensity of the ultraviolet absorption band and the response current increased with the increasing concentration of methylene blue released from the copper-based metal-organic framework. The optical detection range is from 0.10 mg/mL to 10 mg/mL, and the detection limit is 0.10 mg/mL. The electrochemical detection range is from 1.0 × 10⁻⁷ mg/mL to 8.0 × 10⁻⁷ mg/mL, the detection limit is 2.0 × 10⁻⁸ mg/mL. The dual detection strategy, with no interfere with each other, played a synergetic role in the quick qualitative and precise quantitative analyses of<italic> β</italic>-lactoglobulin in a wide range of applications.

Metal organic framework enabled wood evaporator for solar-driven water purification

• Cu-CAT MOF was used as solar absorber for efficient water purification. • The superoleophobic MOF layer was integrated onto the bottom side of wood substrate. • The wood evaporator with a sandwich-like structure presents a good anti-oil-fouling property. • An evaporation rate of 1.80 kg m −2 h −1 under 1 sun illumination was obtained. By utilizing sunlight, the interfacial solar evaporation system is promising for seawater desalination, wastewater decontamination and electricity generation. Herein, a copper-based metal organic framework (Cu-CAT) was coated on wood sheets to form a wood evaporator, and the wood substrate with a low thermal conductivity is in charge of continuous water transportation. The Cu-CAT layer was attached tightly to both the top and bottom surfaces of the wood substrate. The black Cu-CAT at top surface affords a broadband and strong light absorption, while the underwater superoleophobic Cu-CAT layer presents a high oil repellence. Through optimizing the wood substrate thickness, the wood evaporator (Cu-CAT/Wood) with a wood thickness of 10 mm displayed an evaporation rate of 1.80 kg m −2 h −1 under simulated 1 sun illumination. Enabled by the Cu-CAT, the wood evaporator can be used for water purification from various sources (seawater, oil-, dye-, heavy metal- contaminated water and natural lake water). Importantly, the Cu-CAT/Wood could co-generate electricity induced by the solar vaporization process. This work will stimulate more studies on the structural designs of solar evaporators for drinkable water production and pollution abatement.

A copper-based metal–organic framework with a suitable pore environment for effective ethylene purification

Complex 1 based on Cu-MOF with a suitable pore environment and high stability can effectively purify ethylene from any proportion of an ethylene/acetylene mixture.

Non-enzymatic glucose detection via electrochemical methods using copper-based metal-organic frameworks

Non-enzymatic glucose detection via electrochemical methods using copper-based metal-organic frameworks

Construction of Hierarchical Copper-Based Metal-Organic Frameworks Nanosheet Assemblies as an Efficient Electrocatalyst

Construction of Hierarchical Copper-Based Metal-Organic Frameworks Nanosheet Assemblies as an Efficient Electrocatalyst

Polyurethane Foam Incorporated with Nanosized Copper-Based Metal-Organic Framework: Its Antibacterial Properties and Biocompatibility.

Polyurethane foams (PUFs) have attracted attention as biomaterials because of their low adhesion to the wound area and suitability as biodegradable or bioactive materials. The composition of the building blocks for PUFs can be controlled with additives, which provide excellent anti-drug resistance and biocompatibility. Herein, nanosized Cu-BTC (copper(II)-benzene-1,3,5-tricarboxylate) was incorporated into a PUF via the crosslinking reaction of castor oil and chitosan with toluene-2,4-diisocyanate, to enhance therapeutic efficiency through the modification of the surface of PUF. The physical and thermal properties of the nanosized Cu-BTC-incorporated PUF (PUF@Cu-BTC), e.g., swelling ratio, phase transition, thermal gravity loss, and cell morphology, were compared with those of the control PUF. The bactericidal activities of PUF@Cu-BTC and control PUF were evaluated against Pseudomonas aeruginosa, Klebsiella pneumoniae, and methicillin-resistant Staphylococcus aureus. PUF@Cu-BTC exhibited selective and significant antibacterial activity toward the tested bacteria and lower cytotoxicity for mouse embryonic fibroblasts compared with the control PUF at a dose of 2 mg mL−1. The Cu(II) ions release test showed that PUF@Cu-BTC was stable in phosphate buffered saline (PBS) for 24 h. The selective bactericidal activity and low cytotoxicity of PUF@Cu-BTC ensure it is a candidate for therapeutic applications for the drug delivery, treatment of skin disease, and wound healing.

A Copper-Based Metal-Organic Framework for C2H2/CO2 Separation.

A copper-based metal-organic framework, [Cu2(PBTDA)(H2O)2] (UTSA-98, UTSA = the University of Texas at San Antonio; H4PBTDA = 5',5''''-(1,4-phenylene)bis([1,1':3',1″-terphenyl]-4,4″-dicarboxylic acid)), has been solvothermally synthesized. The alternative connection of classical dicopper secondary building units and deprotonated four-branched PBTDA4- ligands led to the formation of the three-dimensional framework of UTSA-98 with one-dimensional rhombic channels. Its guest-free phase, UTSA-98a, uptakes much more C2H2 (82.6 cm3/g) than CO2 (40.3 cm3/g) at 298 K and 100 kPa, resulting in a high adsorption selectivity of 5.2. Furthermore, the efficient separation ability of UTSA-98a toward the C2H2/CO2 gas mixture was further verified by laboratory-scale fixed-bed breakthrough experiments.

Synthesis of Ribose-Coated Copper-Based Metal-Organic Framework for Enhanced Antibacterial Potential of Chloramphenicol against Multi-Drug Resistant Bacteria.

The rise in bacterial resistance to currently used antibiotics is the main focus of medical researchers. Bacterial multidrug resistance (MDR) is a major threat to humans, as it is linked to greater rates of chronic disease and mortality. Hence, there is an urgent need for developing effective strategies to overcome the bacterial MDR. Metal–organic frameworks (MOFs) are a new class of porous crystalline materials made up of metal ions and organic ligands that can vary their pore size and structure to better encapsulate drug candidates. This study reports the synthesis of ribose-coated Cu-MOFs for enhanced bactericidal activity of chloramphenicol (CHL) against Escherichia coli (resistant and sensitive) and MDR Pseudomonas aeruginosa. The synthesized Cu-MOFs were characterized with DLS, FT-IR, powder X-ray diffraction, scanning electron microscope, and atomic force microscope. They were further investigated for their efficacy against selected bacterial strains. The synthesized ribose-coated Cu-MOFs were observed as spherical shape structure with the particle size of 562.84 ± 13.42 nm. CHL caused the increased inhibition of E. coli and MDR P. aeruginosa with significantly reduced MIC and MBIC values after being encapsulated in ribose-coated Cu-MOFs. The morphological analysis of the bacterial strains treated with ribose-coated CHL-Cu-MOFs showed the complete morphological distortion of both E. coli and MDR P. aeruginosa. Based on the results of the study, it can be suggested that ribose-coated Cu-MOFs may be an effective alternate candidate to overcome the MDR and provide new perspective for the treatment of MDR bacterial infections.

Surface-Catalyzed Nitric Oxide Release via a Metal Organic Framework Enhances Antibacterial Surface Effects.

It has been previously demonstrated that metal nanoparticles embedded into polymeric materials doped with nitric oxide (NO) donor compounds can accelerate the release rate of NO for therapeutic applications. Despite the advantages of elevated NO surface flux for eradicating opportunistic bacteria in the initial hours of application, metal nanoparticles can often trigger a secondary biocidal effect through leaching that can lead to unfavorable cytotoxic responses from host cells. Alternatively, copper-based metal organic frameworks (MOFs) have been shown to stabilize Cu2+/1+ via coordination while demonstrating longer-term catalytic performance compared to their salt counterparts. Herein, the practical application of MOFs in NO-releasing polymeric substrates with an embedded NO donor compound was investigated for the first time. By developing composite thermoplastic silicon polycarbonate polyurethane (TSPCU) scaffolds, the catalytic effects achievable via intrapolymeric interactions between an MOF and NO donor compound were investigated using the water-stable copper-based MOF H3[(Cu4Cl)3(BTTri)8-(H2O)12]·72H2O (CuBTTri) and the NO donor S-nitroso-N-acetyl-penicillamine (SNAP). By creating a multifunctional triple-layered composite scaffold with CuBTTri and SNAP, the surface flux of NO from catalyzed SNAP decomposition was found tunable based on the variable weight percent CuBTTri incorporation. The tunable NO surface fluxes were found to elicit different cytotoxic responses in human cell lines, enabling application-specific tailoring. Challenging the TSPCU-NO-MOF composites against 24 h bacterial growth models, the enhanced NO release was found to elicit over 99% reduction in adhered and over 95% reduction in planktonic methicillin-resistant Staphylococcus aureus, with similar results observed for Escherichia coli. These results indicate that the combination of embedded MOFs and NO donors can be used as a highly efficacious tool for the early prevention of biofilm formation on medical devices.

CO2 to ethanol: A selective photoelectrochemical conversion using a ternary composite consisting of graphene oxide/copper oxide and a copper-based metal-organic framework

Photoelectrochemical conversion of CO2 to chemicals has been acknowledged as an advanced and promising approach for the mitigation of carbon dioxide that is a greenhouse gas. However, so far it has mainly been confined to the generation of C1 products like formate, CO, methanol etc. and very few reports are known on the generation of ethanol or higher alcohols. The present work described an efficient PEC reduction of CO2 to ethanol selectively by using a photocathode consisting of a ternary composite containing CuxO/GO and a copper-based metal-organic framework (Cu-MOF). The maximum ethanol yield was found to be 162 uM cm−2 after 4 h at an applied potential of -0.5 V vs Ag/AgCl. The better charge separation, higher mobility and density of photogenerated charge carriers on the interface of nanocomposite led to the higher availability of photo-electrons for CO2 reduction that is further confirmed by the DFT studies. Furthermore, DFT calculations suggested the binding of CO2 over GO/CuxO/Cu-BTC surface via Cu-atoms through the vertical orientation that brought the CO2 molecules closer to the composite and therefore is considered as the most favourable adsorption configuration.

Applications of copper based metal organic frameworks

Frameworks containing organic copper metal are an excellent category of hybrid porous substances gaining significant interest in the past decade. The outstanding features of copper-metal organic frameworks (MOFs) are distinct pore dimensions, different proportions, compatibility, variable configuration, tunable measurements, high loading capacity and upgraded bio-compatibility. These features contribute to making Cu-MOFs potential candidates for drug delivery. Cu-MOFs are a new way to distribute drugs and show how they can effectively distribute various medical substances. Furthermore, several ways that can be employed to improve encapsulation efficiency have been explored. Cu-MOFs have been frequently used as vehicles for delivering medicines to tumour cells with high efficiency. Ultimately, the problems and the prospective for the upcoming progress of copper-containing metal–organic frameworks as effective medication release mechanisms were thoroughly reviewed. As a result, the drug delivery approach based on Cu-MOFs has tremendous scientific significance. This review covers the most recent implementations in 3D Cu-MOF arrangements, from composition to their bio-related interests in fields like drug administration, imaging, sensing, and hydrogen storage. Also, various features and functionalities of modified and unmodified Cu-MOFs for use in regulated medication release applications are presented.

Synthesis of α-amino phosphonates catalyzed by copper-based metal organic frameworks

In this paper we report a novel and straightforward method for the synthesis of α-amino phosphonates via three-component reaction of amines, aldehydes, and triethyl phosphite in the presence of Cu2(BDC)2DABCO (Cu-MOF) as a recyclable heterogeneous catalyst. The chemical structures of the all synthesized compounds were confirmed by NMR, IR and CHN analysis.

Boosting photo-Fenton process enabled by ligand-to-cluster charge transfer excitations in iron-based metal organic framework

Iron-based metal organic frameworks (MOFs) are widely adopted to mediate heterogeneous photo-Fenton reaction, but poor charge separation efficiency in iron-oxo clusters of MOF usually results in the dull Fe(III)/Fe(II) transformation. In this study, ligand-to-cluster charge transfer (LCCT) excitations were first introduced to photo-Fenton process toward accelerating Fe(III)/Fe(II) transformation by constructing new iron-based MOF nanorods with porphyrin ligand (Fe-TCPP). Fe-TCPP with LCCT excitations showed a maximum kinetic constant of 0.23 min-1 for ciprofloxacin (CIP) degradation at neutral pH under visible light irradiation, which is remarkably better than most of the state-of-the-art photocatalysts. Experimental and theoretical analyses collaboratively verify that LCCT excitations within Fe-TCPP dramatically accelerate Fe(III)/Fe(II) transformation, which generate more ∙OH for quick CIP elimination. Additionally, this LCCT excitations strategy is also effective for the photo-Fenton-like system induced by copper-based MOFs. Our study presents a novel strategy to intensify MOFs based photo-Fenton/Fenton-like processes, upon which the high-efficiency contaminant removal is expected.

Synthesis of copper-based metal-organic framework for sensing nitroaromatic compounds

Nitroaromatic compounds in environmental contaminants have threatened human health due to their toxicity and explosivity. MOFs used to environmental contaminants detection has the advantages of highly sensitivity, low cost and rapid response. In this work, the luminescent copper-based metal-organic framework (Cu-MOF) was solvothermally synthesized and further characterized by single-crystal X-ray diffraction, infrared sprectra and powder X-ray diffraction (PXRD). The selectivity and sensitivity of the Cu‐MOF against nitroaromatic compounds were investigated and the limit of detection for 2-nitrophenol sodium salt was 0.0651 μM. In summary, Cu-MOF can be used as a potential highly selective luminescence sensor for 2-nitrophenol sodium salt.

Cyclization of Propargylamines with CO2 on Copper-Based Metal–Organic Frameworks

Cyclization of Propargylamines with CO2 on Copper-Based Metal–Organic Frameworks