Zeolitic Imidazolate Framework Research Articles

Precision Treatment of Colon Cancer Using Doxorubicin-Loaded Metal-Organic-Framework-Coated Magnetic Nanoparticles.

Due to the limited efficacy and evident side effects of traditional chemotherapy drugs attributed to their lack of specificity and selectivity, novel strategies are essential for improving cancer treatment outcomes. Here, we successfully engineered Fe3O4 magnetic nanoparticles coated with zeolitic imidazolate framework-8 (ZIF-8). The resulting nanocomposite (Fe3O4@ZIF-8) demonstrates efficient adsorption of a substantial amount of doxorubicin (DOX) due to the porous nature of ZIF-8. The drug-loaded nanoparticles, Fe3O4@ZIF-8/DOX, exhibit significant accumulation at the tumor site in SW620 colon-cancer-bearing mice when guided by an external magnetic field. Within the acidic microenvironment of the tumor, the ZIF-8 framework collapses, releasing DOX and effectively inducing tumor cell death, thereby inhibiting cancer progression while not causing undesired side effects, as confirmed by a variety of in vitro and in vivo characterizations. In comparison to free DOX, Fe3O4@ZIF-8/DOX nanoparticles show superior efficacy in colon cancer treatment. Our findings suggest that Fe3O4@ZIF-8 holds promise as a carrier for small-molecule drug adsorption and its ferromagnetic properties provide drug targeting capabilities, thereby enhancing therapeutic effects on tumors at the same drug dosage. With excellent biocompatibility, Fe3O4@ZIF-8 demonstrates potential as a drug carrier in targeted cancer chemotherapy. Our work suggests that a combination of magnetic targeting and acid-responsiveness holds great promise for advancing targeted cancer therapy in precision nanomedicine.

Iron and nitrogen co-doped carbon catalysts derived from ZIF-8 towards enhanced peroxymonosulfate activation and contaminants removal: The synergistic effects of FeNx and α/γ-Fe species

The performance upgrading of iron and nitrogen co-doped carbon (Fe-N-C) for peroxymonosulfate (PMS) activation towards contaminants removal and elucidation of the activation mechanism still remains a challenge. In this study, novel iron and nitrogen co-doped carbon (Fe-N-C) catalysts are fabricated through pyrolysis of Fe-modified zeolitic imidazolate framework-8 (ZIF-8) nanocrystals. Catalytic experiments prove that synergistic effects of FeNx and α/γ-Fe species can boost peroxymonosulfate activation and pollutants degradation. Density functional theory simulations disclose that α/γ-Fe species can optimize the d-band center of FeNx and adsorption energy for PMS activation, and thus achieve the enhanced catalytic activities for degradation process. Mechanism studies testify that Fe-N-C-PMS* complex and 1O2 are main contributors for the catalytic process. This work paves a new way for elaborate design of high-performance Fe-N-C materials and understanding about the non-radical mechanism during environmental applications.

Long cycle life aqueous zinc-ion battery enabled by a ZIF-N protective layer with electron-withdrawing group and zincophilicity on the Zn anode

Aqueous zinc-ion batteries (AZIBs) have garnered attention from researchers for their high theoretical capacity, safety, and low cost. However, the uncontrolled growth of zinc (Zn) dendrites and spontaneous corrosion reactions on the Zn anode significantly compromise the cycle life of AZIBs. This paper proposes the utilization of a novel zeolitic imidazole framework (ZIF-N) material with zincophilicity and hydrophilicity for modifying the Zn anode of AZIBs. ZIF-N incorporates numerous electron-withdrawing nitro groups at the Zn/ZIF-N interface to regulate the uneven electron distribution on the Zn anode. The modified Zn anode (Zn@ZIF-N) exhibits a lower polarization ratio (32.18 mV at 4 mA cm−2) and an extended cycle life (over 700 h at 4 mA cm−2). At a current density of 1 mA cm−2, the battery composed of a Zn@ZIF-N anode and NVO (NaV3O8) achieves a cycle life of 1600 cycles. This work provides a straightforward and cost-effective strategy for modifying the Zn anode to prolong the cycle life of AZIBs.

Laser‐Induced Transformation of ZIF‐8 into Highly Luminescent N‐Doped Nanocarbons for Flexible Sensors

AbstractMetal–organic frameworks (MOFs) like the zeolitic imidazolate framework (ZIF‐8) have a high surface area, tunable porosity, and robust thermal and chemical stability, making them attractive candidates for various applications. Here, a strategy is shown that spans that functionality and provides strong photoluminescence (PL) emission, unlocking ZIF‐8‐based materials for chemical and temperature sensors based on PL. The approach is based on laser processing that dramatically boosts the PL response of laser‐irradiated ZIF‐8 (LI ZIF‐8), achieving a 70‐fold increase in intensity relative to the pristine material. The PL characteristics of the irradiated material can be easily tuned by varying the laser power and irradiation time with in situ and real‐time spectroscopic analysis providing insights into the process dynamics. It is found that the observed PL enhancement is primarily due to the laser‐induced transformation of ZIF‐8 into nitrogen‐doped nanocarbons and ZnO nanostructures. The versatility of this laser processing approach is leveraged to create flexible electronics by integrating the LI ZIF‐8/nanocarbon architectures into thermoplastic polyurethane (TPU). The multifunctional composite material shows excellent performance as flexible electrodes for human‐body monitoring applications, as well as both temperature and flexure sensors with remarkable mechanical resilience.

Facile Fabrication of Zeolitic Imidazolate Framework-8@Regenerated Cellulose Nanofibrous Membranes for Effective Adsorption of Tetracycline Hydrochloride

The excessive utilization of antimicrobials in humans and animals has resulted in considerable environmental contamination, necessitating the development of high-performance antibiotic adsorption media. A significant challenge is the development of composite nanofibrous materials that are both beneficial and easy to fabricate, with the aim of improving adsorption capacity. Herein, a new kind of zeolitic imidazolate framework-8 (ZIF-8)-modified regenerated cellulose nanofibrous membrane (ZIF-8@RC NFM) was designed and fabricated by combining electrospinning and in situ surface modification technologies. Benefiting from its favorable surface wettability, enhanced tensile strength, interconnected porous structure, and relatively large specific surface area, the resulting ZIF-8@RC NFMs exhibit a relatively high adsorption capacity for tetracycline hydrochloride (TCH) of 105 mg g−1 within 3 h. Moreover, a Langmuir isotherm model and a pseudo-second-order model have been demonstrated to be more appropriate for the description of the TCH adsorption process of ZIF-8@RC-3 NFMs. Additionally, this composite fibrous material could keep a relatively stable adsorption capability under various ionic strengths. The successful fabrication of the novel ZIF-8@RC NFMs may shed light on the further development of wastewater adsorption treatment materials.

Investigating the Structure of Defects in Heterometallic Zeolitic Imidazolate Frameworks ZIF-8(Zn/Cd) and Its Interaction with CO2 Using First-Principle Calculations

Inducing defect in metal-organic frameworks (MOFs) is one of the strategies to modify the structure and properties of this functional material. Defect may occur in a pristine MOF due to missing organic linkers, metal centres and/or other structural behaviours. In this study, the structure of defects in multicomponent MOFs especially heterometallic MOFs of zeolitic imidazolate framework (ZIF-8(Zn/Cd)) was examined to unveil the possible preference defect formation due to missing 2-methylimidazolate (MeIm) and metal centres of Cd2+ and Zn2+. Assuming defect formation due to the reaction between ZIF-8(Zn/Cd) and water, MeIm linker removal is energetically lower than removing metal centres of either Cd2+ or Zn2+. But, the MeIm linker is easier to be removed when it is connected to Cd2+ (Cd-MeIm-Cd) than when it is connected to Zn2+ (Zn-MeIm-Zn). Defect in ZIF-8(Zn/Cd) affects the band gap energy to give slightly lower value than it in pristine ZIF-8(Zn/Cd). Non-covalent interaction (NCI) and interaction region indicator (IRI) analyses were also performed to indicate possible intermolecular forces such as van der Waals and attractive forces present in non-defective and defective ZIF-8(Zn/Cd). The presence of defects in mixed-metal ZIF-8(Zn/Cd) was also tested for its potential use on CO2 adsorption. The interaction energy of CO2 inside defective ZIF-8(Zn/Cd) indicates an exothermic behaviour where CO2 molecule has a preference to be adsorbed inside the framework. This is especially when the capping agents at the defective ZIF-8(Zn/Cd) sites are removed to give open metal sites. This study provides insight how defects in multicomponent MOFs might presence affecting the structural and properties changes. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Novel [plant essential oils@γ-CD MOF]/ZIF-8 strategy to remove bacteria and dye from bacterial staining wastewater

A novel MOF-on-MOF ([plant essential oils@γ-CD MOF]/ZIF-8) strategy was established in this work, in which a cyclodextrin metal–organic framework (γ-CD MOF) loaded with plant essential oils (cinnamon and oregano oils, COEO) was combined with zeolitic imidazolate framework (ZIF-8) to produce ([COEO@γ-CD MOF]/ZIF-8) for the removal of bacteria and dyes from bacterial staining wastewater. Adsorption isotherm and kinetic studies showed that [COEO@γ-CD MOF]/ZIF-8 could adsorb methylene blue (MB) by monolayer chemisorption with a Qmax of 111.6 mg/g. No bacterial colonies grew on plates treated with [COEO@γ-CD MOF]/ZIF-8, and scanning electron microscope (SEM) images showed a disruption of E. coli and S. aureus structures. This work offers a simple and green method for treating bacterial staining wastewater in microbiology labs.

Lithiophilic Reduced Graphene Oxide/Carbonized Zeolite Imidazolate Framework-8 Composite Host for Stable Li Metal Anodes

Lithiophilic Reduced Graphene Oxide/Carbonized Zeolite Imidazolate Framework-8 Composite Host for Stable Li Metal Anodes

Porous titanium scaffolds modified with Zeolitic Imidazolate Framework (ZIF-8) with enhanced osteogenic activity for the prevention of implant-associated infections

Porous titanium scaffolds modified with Zeolitic Imidazolate Framework (ZIF-8) with enhanced osteogenic activity for the prevention of implant-associated infections

CFD Simulation of Chaotic Flow Characteristics in an Oscillating Feedback Microreactor and Its Application for Preparing Zeolitic Imidazolate Framework-8 Nanoparticles

CFD Simulation of Chaotic Flow Characteristics in an Oscillating Feedback Microreactor and Its Application for Preparing Zeolitic Imidazolate Framework-8 Nanoparticles

In-situ co-growth of ZIF-8-derived bio-carbon spheres with meso-macroporous hierarchy for stable and rapid carbon dioxide capture

Efficient carbon dioxide (CO2) capture from post-combustion flue gases is crucial for industrial applications. Adsorbents with high adsorption capacity, exceptional stability, high selectivity, and low cost are essential to meet these requirements. In this study, we present the synthesis of bio‑carbon spheres derived from zeolitic imidazolate framework-8 (ZIF-8) using a macro-fluidic technique. The bio‑carbon spheres integrate ZIF-8 for structural orientation and chitosan for the directional assembly of ZIF-8, thereby addressing the limitations of low strength in chitosan-derived carbon spheres and the challenge of macroscopic shaping of ZIF-8 particles. Additionally, the incorporation of ZIF-8 and the enhancement of the carbon skeleton increased the meso-macroporosity, improving CO2 transport and adsorption performance. The bio‑carbon spheres demonstrated a 46.9% higher CO2 adsorption capacity (101 kPa, 1.40 mmol·g−1) compared to pure chitosan carbon granules (101 kPa, 0.96 mmol·g−1) and a 17.8% faster mass transport rate compared to ZIF-8 carbon particles. Moreover, the bio‑carbon spheres exhibit a low wear rate in a simulated fluidized bed, good thermal stability, and stable cyclic regeneration performance. This study offers a novel strategy for developing industrially applicable adsorbents with hierarchical pore structures to enhance CO2 capture.

Aqueous co-solvent synthesis of Zeolitic Imidazolate Frameworks: The impact of co-solvents in the crystal growth kinetics

Zeolitic Imidazolate Frameworks (ZIFs) have been widely studied in recent decades in a variety of applications. However, a fundamental understanding of crystal growth kinetics as well as their formation mechanisms has been very limited. Underpinning such mechanisms might be of key importance for the predictable synthesis of ZIFs to rationally tune the structural and morphological properties for respective applications. Herein, the crystal growth kinetics and structural evolution of ZIF-8 crystals in various aqueous co-solvent reaction environments were studied with respect to synthesis time. By tracking the nucleation, crystal growth, stabilization and ripening, three potential kinetic formation mechanisms were proposed. More specifically, with methanol, isopropanol and acetone, a fast nucleation rate and crystal growth occurred within 60 minutes (min) at room temperature. However, ethanol and n-propanol showed prolonged nucleation which resulted in the slow formation of ZIF-L/ZIF-8 mixed phases at the early stage. Phase transformation to pure ZIF-8 was observed in longer syntheses. Nitrogen-containing solvent, N, N–dimethyl formaldehyde (DMF), was found to induce both nucleation and growth, resulting in large crystals in less than 60 min of fabrication. In each case, the crystal formation follows Avrami's classical model. Hence, by understanding the effects of co-solvents in ZIF nucleation, crystallization and phase selection, one can rationally design the crystals with predictable crystallinity, size, morphology, purity and surface properties for targeted applications such as adsorption of small molecules from aqueous mixtures.

Preparation and performance studies on organic-inorganic phase change composites based on zeolitic imidazolate and paraffin for reducing gun barrel erosion

With the increasing requirements of tank guns for higher muzzle velocity and faster firing rate, some high energetic additives, such as cyclotrimethylene trinitramine (RDX) and cyclotetramethylene tetranitramine (HMX), have been widely used in high energy gun propellants. Consequently, the gun barrel erosion induced by the burning of high energy gun propellants has been an important issue that affects the lifespan of gun barrels. In order to address this problem, erosion reducing additives, including TiO2, paraffin, polyurethane or a combination of these, were introduced into the gun propellant or propellant charge system to alleviate the gun barrel erosion. In this study, a novel organic-inorganic phase change composite paraffin/ZIF-67 with solid paraffin (SP) as the phase change component and zeolitic imidazolate framework-67 (ZIF-67) as the matrix was designed and prepared as anti-erosion additives. The designed composite has a high thermal storage capacity of 93.88 J/g when the ZIF-67 content is 5 wt%. The erosion reducing effect of paraffin/ZIF-67 was determined by erosion tube test. The results show that the introduction of paraffin/ZIF-67 can improve the erosion-reducing efficiency of gun propellants. Compared with the control sample, the erosion-reducing efficiency of paraffin/ZIF-67 exhibited a faster increase with the increase of their contents, having the maximum erosion-reducing efficiency of 39.2 % when the addition of paraffin/ZIF-67 is 3.2 wt%. The incorporation of paraffin/ZIF-67 in the composites has a cooperative effect of each component on reducing gun barrel erosion. The developed organic-inorganic phase change composites exhibit great potential in the application of reducing gun barrel erosion, providing a new way for the development of erosion reducing additives.

Dual-Porous ZIF-8 Heterogeneous Catalysts with Increased Reaction Sites for Efficient PET Glycolysis

Poly(ethylene terephthalate) (PET) has been widely used for drink bottles, food packing, films, and fibers, resulting in millions of tons of waste PET. Less than 10% of that waste is recycled, and the rest is discarded or incinerated. Waste PET upcycling employs chemical recycling and particularly glycolysis to create the bis(2-hydroxyethyl) terephthalate (BHET) monomer. Herein, we report a dual-porous zeolitic imidazolate framework-8 nanoparticle (DPZIF-8) heterogeneous catalyst for efficient PET glycolysis. The DPZIF-8 nanoparticles were prepared using a triethylamine modulator, which can control the nucleation and growth mechanisms of the ZIF-8 nanoparticles. The DPZIF-8 nanoparticles include both intrinsic micropores and particle-particle adhesion-induced mesopores that can provide a larger external surface area of the zinc sites in the ZIF-8 architecture. The PET glycolysis catalyzed by DPZIF-8 at 180 °C and 1 atm for 4 h shows a PET conversion of 91.7% and a BHET yield of 76.1%, the latter particularly being much higher than with a traditional heterogeneous ZIF-8 catalyst. This dual-porous structure rational design strategy can be versatile for other metal–organic frameworks (MOFs) to increase the interfacial catalytic reaction sites between the metal–organic framework and the polymer, enhancing the PET depolymerization performance and efficiency.

A non-destructive strategy to construct ZIF-8 interface layer of carbon fiber/hydroxyapatite-epoxy composites

The interface is the transition region between the fiber and the matrix, whose structure and characteristics determine the overall performance and sustained stability of carbon fiber/hydroxyapatite-epoxy (CHR) composites as bone implant materials. Similarly, carbon fibers, as reinforcement, also play an indispensable role in carrying external loads. Therefore, this work focuses on improving the fibers surface in a gentle and non-destructive way to ensure that the reinforcement of both the fibers and the interface is maximized, resulting in excellent mechanical and biotribological properties. In this work, a novel interface layer was designed by introducing zeolitic imidazolate framework-8 (ZIF-8) into CHR with a facile solvent method. The presence of ZIF-8 induces the formation of flower-cluster hydroxyapatite. The complex layer formed by the combination of the polyhedral shape ZIF-8 and the flower-cluster hydroxyapatite enhances the mechanical interlock and chemical interaction between the carbon fibers and the epoxy matrix. It also promotes the penetration and curing process of the epoxy matrix. The tensile strength of ZIF-8 reinforced CHR (ZIF-8@CHR) are 136.97 MPa, which is 38.43 % higher than that of the pristine CHR. And the wear rate (1.18 × 10−14 m3(N·m)−1) of ZIF-8@CHR is decreased by 81.65 %. ZIF-8@CHR with superior mechanical and biotribological properties provides new insights into the biological application of carbon fiber composites as an implant material for fracture fixation or reconstruction.

Synthesis of Pt-doped CoFe layered double hydroxide derived from zeolitic imidazolate framework for efficient electrochemical oxygen evolution reaction

Zeolitic imidazolate frameworks (ZIFs), a class of promising metal organic frameworks (MOFs) material, display high porosity and chemical/thermal stability. However, there are problems such as few active sites and restricted exposed active areas, which limit the oxygen evolution reaction (OER) performance of catalysts. Here, starting from zeolitic imidazolate framework-67 (ZIF-67), we have successfully synthesized Pt-doped CoFe layered double hydroxide (Pt/CoFe LDH) catalysts for efficient OER catalysis. The obtained Pt/CoFe LDH-4 catalysts provides large surface areas and abundant active sites, which further improves the OER performance. In detail, the Pt/CoFe LDH-4 exhibits a lower overpotential of 263 mV at a current density of 40 mA cm−2, in 1 M KOH solution, the stability of the catalyst exceeds 120 h at this current density, far superior to commercial catalyst RuO2. This study describes a new design idea for synthesis of LDH catalytic materials with low noble metal doping, which broadens the way to the synthesis of robust OER catalysts derived from ZIF-67.

Incorporation of zeolitic imidazolate framework-8 (ZIF-8) in the polyamide and polysulfone layers of forward osmosis membranes for enhancing aquaculture wastewater recovery and PPCPs removal

Wastewater recovery is essential to alleviate water resource shortages, and this can be achieved through a high-energy-efficient forward osmosis (FO) process combined with an emerging material, zeolitic imidazolate framework-8 (ZIF-8). Here, we create thin-film composite FO membranes (TF-CFOMs) by incorporating ZIF-8 into the active polyamide (PA) and/or support polysulfone (PSf) layers to address the challenges of low water flux and loss of draw solutes during operation. Experimental factors included the dosage of ZIF-8 nanoparticles in PA preparation solutions and the dosages of 2-methylimidazole (2-Hmim) and zinc nitrate hexahydrate (ZNH) in n-methyl-2-pyrrolidone (NMP) to fabricate the PSf casting solutions with in-situ formed ZIF-8 nanoparticles. Successful ZIF-8 incorporation on the TF-CFOM surface was confirmed, and the ZIF-8 TF-CFOMs exhibited increased surface hydrophilicity and separation performance. Only modifying the PA layer by adding 0.025 wt% ZIF-8 nanoparticles in trimesoyl chloride (TMC) resulted in the membrane (PA0.025T-PSf0) with water flux 2.3 times higher than the pristine TF-CFOM (4.9 LMH). The pristine and modified TF-CFOMs were further applied for aquaculture wastewater (AWW) recovery and removal of pharmaceuticals and personal care products (PPCPs). Results of water recovery demonstrated that the recovery rate reached 89.1% in 3.5 days when using the dual-layer modified TF-CFOM. Results of PPCP removal indicated that both pristine and modified TF-CFOMs can achieve high PPCP rejection efficiency (>90%), with the modified TF-CFOM (PA0.025T-PSf2.0) performing the best. Overall, the PA0.025T-PSf2.0 TF-CFOM achieved high and stable separation efficiency in long-duration AWW recovery, making it well-suited for practical field applications.

Design of ZIF-8-based PVB composite coating on AZ31B Mg alloy surface with superhydrophobic, wear, corrosion protection and durability

Magnesium (Mg) alloys are susceptible to being attacked by corrosive ions in practical application environments, which limits their widespread application as the most promising engineering material. Herein, the superhydrophobic composite coating PVB/STA/ZIF-8@SiO2 (PSZS) has been designed on the surface of Mg alloy by using a drop coating method to improve its corrosion resistance. In this study, we provide an approachable decoration strategy for hydrophobic and hierarchical modification of zeolite imidazolate frameworks (ZIF-8) with stearic acid (STA) and SiO2, and combined with polyvinyl butyral (PVB) to form a composite coating with excellent performance on the substrate surface. Notably, the PSZS composite coating exhibited superhydrophobic and the contact angle is greater than 150° after 300 cm of mechanical friction. The electrochemical testing of the PSZS composite coating indicated that it greatly protected the Mg alloys from corrosion. Moreover, the PSZS coating displayed highly effective corrosion resistance even after being immersed in 3.5 wt% NaCl aqueous solution for 7 days. Overall, the PSZS composite coating with the advantages of corrosion resistance, corrosion durability, superhydrophobic, abrasion resistance and simple preparation process broadens the horizons of Mg alloy corrosion resistance research.

CuO@N/C-ZnO nanoflowers with quantum dots derived from ZIF-8 for efficient CO2 photoreduction

In this pioneering work, an innovative photocatalyst, denoted as the porous erythrocytic-like nanoflower derived from zeolitic imidazolate framework (ZIF-8) (CuO@N/C-ZnONF), has been meticulously crafted. This design integrates a porous nanosheet of nitrogen and carbon co-doped ZnO, strategically refined with CuO nanosheets (CuONS) architecture originating from ZIF-8. This innovative nanomaterial serves as a nanoreactor for converting CO2 into CO and CH4. The distinctive porous nanoflower structure facilitates enhanced mobility of charge carriers throughout the accessible framework, maximizes exposure of active sites, and improves the flow of charge carriers while preventing their recombination. Additionally, the porous characteristics facilitate the diffusion of reactants and products. The synthesized 10CuO/N-C-ZnONF demonstrates superior photocatalytic performance, yielding high CO and CH4 outputs of 286.16 and 39.74 µmol g−1h−1, respectively, and exhibits excellent long-term stability.

Development of Zeolite Imidazole Framework-Based Adsorbent for Effective Microextraction and Preconcentration of Histamine in Food Samples.

This study is the first to focus on the preconcentration and determination of histamine (HIS) in food samples using zeolite imidazole frameworks (ZIFs) on a solid-phase microextraction (SPME) platform. ZIF was developed on a polypropylene hollow fiber (PPHF) substrate (ZIF@PPHF) and characterized. The extraction performance was optimized by adjusting several parameters, including pH, contact time for adsorption, and desorption conditions. Under the optimized conditions, a wide linear dynamic range (0.05-250 mg/L) with high R2 values (0.9989), low limit of detection (0.019 mg/L), and low limit of quantification (0.050 mg/L) were determined as analytical figures of merit. Additionally, a reusability study confirmed that ZIF@PPHF preconcentrated 83% of the HIS up to the fourth cycle. The developed method was used to preconcentrate HIS in fish and cheese samples. The spiked real samples confirmed the validity and accuracy of this method. The percentage mean recoveries ± relative standard deviation (% RSD, n = 3) at the concentration levels of 5, 10, and 50 mg/L of HIS and the sample amount of 5 g for intra- and inter days ranged from 97 ± 1.10 to 102.80 ± 0.90 and from 96.40 ± 1.82 to 103.40 ± 0.79, respectively. The results suggest that the analytical method validation parameters were acceptable, indicating the repeatability and sensitivity of the method.