Metal-organic Frameworks Nanostructures Research Articles

Advancements in wastewater Treatment: A computational analysis of adsorption characteristics of cationic dyes pollutants on amide Functionalized-MOF nanostructure MIL-53 (Al) surfaces

Recently, research has become increasingly concerned with removing cationic synthetic dyes from the environment because of their aromatic rings and ecological stability, which causes serious health risks for humans and other living organisms. A dye-adsorption system is widely acknowledged as one of the most reliable and practical approaches to wastewater treatment, which is verified for its high effectiveness, low cost, simplicity, and adsorbent reusability. Interestingly, metal–organic frameworks (MOFs) have gained immense attention for their applications in removing dye pollutants from water. This study investigates the adsorption characteristics of well-known cationic dye pollutants, comprising Malachite green (MG), Rhodamine B (RHB), Methylene blue (MB), Toluidine Blue (TB), Gentian violet (GV), Neutral red (NR) on MOF nanostructures functionalized with amide groups using amide/MIL-53 (Al) in two acidic and basic environments via a multiscale computational approach, including Monte Carlo (MC), molecular dynamics (MD) simulations, quantum mechanics tools. The adsorption behaviour of amide/MIL-53 (Al) adsorbent was discussed regarding dye hydration, the role of the nature of the central metal, missing linker defects (MLDs) and missing cluster defects (MCDs) in its structure. The results showed that the amide/MIL 53 had a high adsorption capacity for the cationic dyes because of its robust interaction with positive charges on the dye molecules. The high adsorption potential was assigned to various interactions between the dyes and the adsorbent, including π-π stacking, van der Waals and electrostatic interactions, hydrogen bonding and other weak interactions. According to our findings, the benzene rings of RHB dyes interact more strongly with amide/MIL-53 (Al) surfaces owing to their higher π–π stack bonding energies and hydrogen bonding. The computational study also played a crucial role in predicting the cationic dye adsorption behaviour on the amide/MIL-53 (Al) nanostructure surfaces. The findings of this study have significant implications for the design and development of advanced adsorbent materials for removing cationic dye pollutants from contaminated water.

BioMOF-Based Anti-Cancer Drug Delivery Systems.

A variety of nanomaterials have been developed specifically for biomedical applications, such as drug delivery in cancer treatment. These materials involve both synthetic and natural nanoparticles and nanofibers of varying dimensions. The efficacy of a drug delivery system (DDS) depends on its biocompatibility, intrinsic high surface area, high interconnected porosity, and chemical functionality. Recent advances in metal-organic framework (MOF) nanostructures have led to the achievement of these desirable features. MOFs consist of metal ions and organic linkers that are assembled in different geometries and can be produced in 0, 1, 2, or 3 dimensions. The defining features of MOFs are their outstanding surface area, interconnected porosity, and variable chemical functionality, which enable an endless range of modalities for loading drugs into their hierarchical structures. MOFs, coupled with biocompatibility requisites, are now regarded as highly successful DDSs for the treatment of diverse diseases. This review aims to present the development and applications of DDSs based on chemically-functionalized MOF nanostructures in the context of cancer treatment. A concise overview of the structure, synthesis, and mode of action of MOF-DDS is provided.

Tightened 1D/3D carbon heterostructure infiltrating phase change materials for solar–thermoelectric energy harvesting: Faster and better

AbstractExtensive use of thermal energy in daily life is ideal for reducing carbon emissions to achieve carbon neutrality; however, the effective collection of thermal energy is a major hurdle. Thermoelectric (TE) conversion technology based on the Seebeck effect and thermal energy storage technology based on phase change materials (PCMs) represent smart, feasible, and research‐worthy approaches to overcome this hurdle. However, the integration of multiple thermal energy sources freely existing in the environment for storage and output of thermal and electrical energy simultaneously still remains a huge challenge. Herein, three‐dimensional (3D) nanostructured metal–organic frameworks (MOFs) are in situ nucleated and grown onto carbon nanotubes (CNTs) via coordination bonding. After calcination, the prepared core–shell structural CNTs@MOFs are transformed into tightened 1D/3D carbon heterostructure loading Co nanoparticles for efficient solar–thermoelectric energy harvesting. Surprisingly, the corresponding composite PCMs show a record‐breaking solar–thermal conversion efficiency of 98.1% due to the tightened carbon heterostructure and the local surface plasmon resonance effect of Co nanoparticles. Moreover, our designed all‐in‐one composite PCMs are also capable of creating an electrical potential of 0.5 mV based on the Seebeck effect without a TE generator. This promising approach can store thermal and electrical energy simultaneously, providing a new direction in the design of advanced all‐in‐one multifunctional PCMs for thermal energy storage and utilization.

Sustainable 3D Printing of Recyclable Biocomposite Empowered by Flash Graphene.

Sustainability of 3D printing can be reflected in three main aspects: deployment of renewable inks, recycling of printed products, and applications for energy- and materials- savings. In this work, we demonstrated sustainable vat-photopolymerization (VPP)-based 3D printing in a whole life-cycle process by developing a renewable ink made of soybean oil and natural polyphenols and recycling the ink for reprinting or converting printed biocomposite to flash graphene (FG) as reinforcing nanofillers in the biocomposite. We also realized its applications in fabricating lightweight, materials-saving 3D structures, acoustic metamaterials, and disposable microreactors for time-saving and efficiency-improving synthesis of metal-organic framework nanostructures. In addition to enhancing the tensile strength and Young's modulus of the biopolymers by 42% and 232% with only 0.6 wt % FG nanofillers, respectively, FG improved the printability of the ink in forming 3D tubular structures, which are usually very hard to be achieved in transparent resin. Success of this work will inspire further development for sustainability in 3D printing.

Current Progress in 2D Metal–Organic Frameworks for Electrocatalysis

The 2D nanosheets of metal–organic frameworks (MOFs) have recently emerged as a promising material that makes them valuable in widespread electrocatalytic fields due to their atomic‐level thickness, abundant active sites, and large surface area. Efficient electrocatalysts for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting are highly desired with low overpotentials to promote the industrial applications of energy conversion and devices. 2D MOF nanostructures provide long‐term stability and high electrical conductivity to enhance catalyst activity and durability. This review briefly summarizes the synthesis and electrocatalytic applications of 2D MOF for HER/OER/water splitting. More attention is focused on the synthetic strategies of 2D MOF and their derivatives. The catalytic performance and superior properties of these materials are highlighted. The outperformance of these materials originates from the rational design, myriad of abundant active sites, and atomic‐level thickness. The current and future challenges in this field and the scientific perspectives to overcome these challenges are highlighted. It is suggested that the construction of 2D MOF nanostructures can develop a state‐of‐the‐art electrocatalyst in energy and environmental division.

An Efficient Ultrasound-Assisted Synthesis of Cu/Zn Hybrid MOF Nanostructures With High Microbial Strain Performance.

Metal organic frameworks (MOFs) are a promising choice for antibacterial and antifungal activity due to their composition, unique architecture, and larger surface area. Herein, the ultrasonic method was used to synthesize the Cu/Zn-MOF material as an effective hybrid nanostructure with ideal properties. SEM images were used to investigate the product’s morphology and particle size distribution. The XRD pattern revealed that the Cu/Zn hybrid MOF nanostructures had a smaller crystalline size distribution than pure Cu and Zn-MOF samples. Furthermore, the BET technique determined that the hybrid MOF nanostructures had a high specific surface area. TG analysis revealed that the hybrid MOF structures were more thermally stable than pure samples. The final product, with remarkable properties, was used as a new option in the field of antibacterial studies. Antibacterial activity was assessed using MIC and MBC against Gram negative and Gram positive strains, as well as antifungal activity using MIC and MFC. The antimicrobial properties of the synthesized Cu/Zn hybrid MOF nanostructures revealed that they were more effective than commercial drugs in some cases. This study’s protocol could be a new strategy for introducing new hybrid nanostructures with specific applications.

Unusual synthesis of nanostructured Zn-MOF by bipolar electrochemistry in ionic liquid-based electrolyte: Intrinsic alkaline phosphatase-like activity

Metal-organic frameworks (MOFs) as a unique class of multifunctional materials have increasingly attracted interest. So, the development of available and straightforward strategies for the synthesis of MOFs reminds challenging. Here, we developed an indirect bipolar electrodeposition method to construct a novel and fine nanostructured Zn-MOF on the indium tin oxide (ITO) surface. The room temperature ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) is used as an electrolyte, zinc sulfate (monohydrate) as the source of metal ion, and 1,3,5 benzenetricarboxylic acid (BTC) as an organic ligand. The synthesized MOF was characterized by scanning electron microscopy (SEM) along with energy-dispersive X-ray spectroscopy (EDAX), grazing Incidence X-ray Diffraction (GIXRD), atomic force microscopy (AFM), X-ray photo spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. Furthermore, we have explored the structure of Zn-BTC MOF and their enzyme cofactor's similarity to alkaline phosphatase mimics in aqueous solutions. The proposed MOF nanostructures have been investigated as a promoter for hydrolysis of sodium para-nitrophenylphosphate (PNPP) to para-nitrophenol (PNP) and inorganic phosphate.

In-situ growth of 3D Cu-MOF on 1D halloysite nanotubes/reduced graphene oxide nanocomposite for simultaneous sensing of dopamine and paracetamol

Three-dimensional (3D) metal–organic frameworks (MOFs) a class of porous materials with tunable structure and surface functionality has arisen as electrode materials especially, for electrochemical sensing of analytes. However, MOFs possess intrinsic drawbacks such as poor conductivity with an agglomeration of particles, which restricted the electrochemical signal response in terms of sensitivity and detection limits. In this regard, the present work aims to develop conducting Cu-MOF on HNTs, a good substate for in-situ growth of MOF nanostructures due to the existence of abundant negatively charged Si-OH that can help the growth of nanosized MOFs. The negatively charged siloxane (Si-O-Si) groups on the surface of HNTs can be attracted by positive charged Cu2+ ions present in the reaction mixture through strong electrostatic attraction. When subjected to hydrothermal treatment, the Cu2+ ions can form nano-sized Cu-MOF particles with assistance from 2-methylimidazole. Moreover, the presence of graphene oxide (GO) can improve the electrical conductivity, large surface area, and thus resulting in the formation of conducting Cu-MOF/HNTs/rGO nanocomposite. Owing to the synergetic desirable properties of active metal sites and high porosity offered by Cu-MOF, the high conductivity of rGO, and the large surface area of HNTs, the resultant Cu-MOF/HNTs/rGO modified GC electrode demonstrates superior electrochemical signal response towards dopamine and paracetamol. Moreover, the developed sensor exhibits wide linear ranges of 0.1 µM–130 µM and 0.5–250 µM, with a low detection limit of 0.03 µM and 0.15 µM for dopamine and paracetamol, respectively.

An efficient ultrasound-assisted route of a novel Lanthanum (III) metal-organic framework nanostructure as a novel porous material for electrocatalytic activity in oxidation of 4-aminophenol

An efficient ultrasound-assisted route of a novel Lanthanum (III) metal-organic framework nanostructure as a novel porous material for electrocatalytic activity in oxidation of 4-aminophenol

Controlling Metal Clusters in Breathing Metal–Organic Framework Nanostructures for Boosting Visible-Light-Induced ·OH Radical Formation

Controlling Metal Clusters in Breathing Metal–Organic Framework Nanostructures for Boosting Visible-Light-Induced ·OH Radical Formation

Iron-Based 2D Conductive Metal–Organic Framework Nanostructure with Enhanced Pseudocapacitance

Electrically conductive metal–organic frameworks have emerged as an attractive class of materials for sensing and energy storage applications with unique electronic properties. However, the field lacks structural diversity often because of the limited choices for metal nodes. In this regard, the incorporation of iron species has been desirable due to its rich redox chemistry. Herein, we report an Fe-based two-dimensional (2D) electrically conductive MOF with 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP), namely, Fe–HHTP, that shows redox features and mesoporosity. Fe–HHTP exhibits an electrical conductivity of 3.55 × 10–5 S cm–1 despite a large interlayer spacing of ∼6.5 Å due to N,N-dimethylformamide (DMF) coordination on the Fe nodes. Spectroscopic results confirm that Fe–HHTP exhibits a mixed valency of Fe(II)/Fe(III) with Fe(II) being dominant. Fe–HHTP boasts exceptional capacitance and apparent redox activity compared to the previously reported analogues using the same ligand. We envision that Fe–HHTP can be an excellent candidate for applications in chemical sensing and energy storage where discrete redox features are essential.

Pd-Embedded Ti Metal–Organic Framework Nanostructures for Photocatalytic Reductive N-Formylation of Nitroarenes in Water

The photocatalytic reductive N-formylation of nitroarenes is carried out over a Pd nanoparticle (Pd NP)-embedded nanostructured Ti-metal–organic framework (MOF) using sunlight or a household white light-emitting diode (LED). Herein, the Ti-MOF is used as a visible-light-absorbing material, and the Pd NPs boost the photogenerated charge-carrier separation and transfer to the active sites for catalyzing the photocatalytic N-formylation of nitroarenes. The surface characteristics, oxidation states, and elemental compositions of the nanostructured materials were characterized by several physicochemical characterization techniques. Optical property and photoelectrochemical measurements were conducted to determine the bandgap, electron–hole recombination rate, band edge potentials, photocurrent density, charge-carrier separation, and so on. N-formylation of nitroarenes was achieved using HCOOH as a sustainable hydrogen and formylating source with simple household white LED bulbs. The yield of N-formylated arene was excellent in an aqueous medium. The structure–activity relationship was revealed using photocatalytic activity data, physicochemical and optoelectronic characteristics, control experiments, and scavenging studies. The high photocatalytic performance of the Pd/Ti-MOF can be ascribed to the direct contact between the Pd NPs and MOF, the generation of abundant catalytically active sites, and the superior electrical conductivity that leads to rapid electron transfer processes. The Pd/Ti-MOF exhibited excellent photostability and recyclability. The efficient catalyst design, an economical and sustainable light source for the direct formylation of nitroarenes, would attract researchers to develop similar catalytic protocols to other industrially important chemicals.

Conductive Co-based metal organic framework nanostructures for excellent potassium- and lithium-ion storage: kinetics and mechanism studies

Nanostructured Co-CAT metal–organic frameworks show excellent potassium storage performance in terms of high specific capacity, fast charge/discharge and long term storage stability.

Multicolor Random Lasers Based on Perovskite Quantum Dots Embedded in Intrinsic Pb–MOFs

Perovskite quantum dots (PQDs) have attracted extensive attention for various applications due to their hallmark optoelectronic properties. However, PQD gain materials are usually needed to be integrated with an external cavity to acquire effective optical feedback for lasing oscillation, which generally suffers from stringent fabrication procedures and the destruction of their pristine gain performance. In this work, we propose an approach to realize a new class of random lasers that are constructed by in situ precipitating perovskite quantum dots (PQDs) in metal–organic frameworks (MOFs). Such random lasers make full use of the combined merits of MOFs showing a high refractive index and a broad transmission window and that of PQDs exhibiting high optical gain. A lead-based MOF is utilized as a matrix, which allows us to grow PQDs at the Pb2+ sites in situ and thus produce high-density PQDs gain in MOFs. We experimentally demonstrate low-threshold multicolor random lasers achieved in the visible spectral range with different wavelengths through compositional modulation in the nanoporous environment of MOF nanostructures and illustrate potential applications of the developed PQDs@MOFs random laser as the illumination source in the speckle-free optical imaging. This study will pave the way for the construction of perovskite-based lasing in multifunctional systems.

Determination of Buprenorphine (BUP) with Molecularly Imprinted Polymer Zn/La3+ Metal Organic Framework on Modified Glassy Carbon Electrode (GCE)

AbstractIn this study we report the Zn/La3+ metal organic frameworks (MOFs) were synthesized with the co‐precipitation assisted microwave method. Zn/La3+ MOFs were used as a new nanocomposite for the design and construction of a nanosensor based on glassy carbon electrode (GCE). MOFs due to their unique and excellent physicochemical properties can be used in sensors based on glassy carbon electrode (GCE). The synergistic effect of MOFs on glassy carbon electrode increases the power of the limits of detection (LOD). In this study, a new chemical sensor was fabricated by electro polymerization to measure buprenorphine with MOFs based on molecularly imprinted polymer. Zn/La3+ MOFs nanostructures were identified with scanning electron microscopy (SEM), Dynamic light scattering (DLS), Transmission electron microscopy (TEM) and the Fourier‐transform infrared spectroscopy (FT‐IR) spectra. Buprenorphine was used as a template, pyrrole was used as a monomer, potassium ferrocyanide as an electrochemical active tracer in electropolymerization processes and the parameters affecting the sensor response were optimized. At the Zn/La3+ MOF/MIP electrode, the calibration curve in the linear region was obtained in the concentration range between 4 to 50 ng/ml and the detection limit was 1.08 ng/ml. In a new strategy, Zn/La3+ MOFs nanostructures can be introduced as new materials with high efficiency which used at chemical sensors for detection of the opiates in all over the world.

Templated interfacial synthesis of metal-organic framework (MOF) nano- and micro-structures with precisely controlled shapes and sizes

Metal-organic frameworks (MOF) are an emerging class of microporous materials with promising applications. MOF nanocrystals, and their assembled super-structures, can display unique properties and reactivities when compared with their bulk analogues. MOF nanostructures of 0-D, 2-D, and 3-D dimensions can be routinely obtained by controlling reaction conditions and ligand additives, while formation of 1-D MOF nanocrystals (nanowires and nanorods) and super-structures has been relatively rare. We report here a facile templated interfacial synthesis methodology for the preparation of a series of 1-D MOF nano- and micro-structures with precisely controlled shapes and sizes. Specifically, by applying track-etched polycarbonate (PCTE) membranes as the templates and at the oil/water interface, we rapidly and reproducibly synthesize zeolitic imidazolate framework-8 (ZIF-8) and ZIF-67 nano- and micro structures of sizes ranging from 10 nm to 20 μm. We also identify a size confinement effect on MOF crystal growth, which leads to single crystals under the most restricted conditions and inter-grown polycrystals at larger template pore sizes, as well as surface directing effects that influence the crystallographic preferred orientation. Our findings provide a potentially generalizable method for controlling the size, morphology, and crystal orientations of MOF nanomaterials, as well as offering fundamental understanding into MOF crystal growth mechanisms.

Metal-Organic-Framework-Derived Nanostructures as Multifaceted Electrodes in Metal-Sulfur Batteries.

Metal-sulfur batteries (MSBs) are considered up-and-coming future-generation energy storage systems because of their prominent theoretical energy density. However, the practical applications of MSBs are still hampered by several critical challenges, i.e., the shuttle effects, sluggish redox kinetics, and low conductivity of sulfur species. Recently, benefiting from the high surface area, regulated networks, molecular/atomic-level reactive sites, the metal-organic frameworks (MOFs)-derived nanostructures have emerged as efficient and durable multifaceted electrodes in MSBs. Herein, a timely review is presented on recent advancements in designing MOF-derived electrodes, including fabricating strategies, composition management, topography control, and electrochemical performance assessment. Particularly, the inherent charge transfer, intrinsic polysulfide immobilization, and catalytic conversion on designing and engineering of MOF nanostructures for efficient MSBs are systematically discussed. In the end, the essence of how MOFs' nanostructures influence their electrochemical properties in MSBs and conclude the future tendencies regarding the construction of MOF-derived electrodes in MSBs is exposed. It is believed that this progress review will provide significant experimental/theoretical guidance in designing and understanding the MOF-derived nanostructures as multifaceted electrodes, thus offering promising orientations for the future development of fast-kinetic and robust MSBs in broad energy fields.

Two-Dimensional Metal–Organic Framework Nanostructures Based on 4,4′-Sulfonyldibenzoate for Photocatalytic Degradation of Organic Dyes

Two-Dimensional Metal–Organic Framework Nanostructures Based on 4,4′-Sulfonyldibenzoate for Photocatalytic Degradation of Organic Dyes

Bimetallic Ce/Zr UiO-66 Metal–Organic Framework Nanostructures as Peptidase and Oxidase Nanozymes

The catalytic activity of metal–organic frameworks (MOFs) toward peptides and proteins provides an attractive route for the development of nanozymes for applications in biotechnology and proteomics...

Rational Design of a Dual-Layered Metal-Organic Framework Nanostructure for Enhancing the Cell Imaging of Molecular Beacons.

As the most popular nucleic acid probe, molecular beacons (MBs) can selectively light up endogenous RNA targets without specific treatment. However, the poor cell permeability and unsatisfied intracellular stability of MBs significantly restricted their detection performance. Herein, we report the encapsulation of MB within a dual-layered metal-organic framework nanostructure UiO66-ZIF8 for enhanced cell imaging. UiO66-NH2 nanoparticles were synthesized as the template for MB loading, and the ZIF-8 shell was further coated on the surface of UiO66-MB to ensure its stability and lysosomal escape effect. Taking multidrug-resistant (MDR1) mRNA as a model target, MBs loaded within UiO66-ZIF8 showed an improved lysosomal escape effect compared with MB absorbed on UiO66-NH2. Therefore, efficient and accurate intracellular MDR1 mRNA imaging was realized with UiO66-MB-ZIF8. This work presented a new method for the rational regulation of the intracellular fate of MOF-based nanoprobes and will facilitate the further development of hierarchical MOF nanoprobes for analytical applications.