Zeolitic Imidazolate Framework Research Articles

Kumquat peel-derived biochar to support zeolitic imidazole framework-67 (ZIF-67) for enhancing peracetic acid activation to remove acetaminophen from aqueous solution

This study presents the synthesis of a novel composite catalyst, ZIF-67, doped on sodium bicarbonate-modified biochar derived from kumquat peels (ZIF-67@KSB3), for the enhanced activation of peracetic acid (PAA) in the degradation of acetaminophen (APAP) in aqueous solutions. The composite demonstrated a high degradation efficiency, achieving 94.3% elimination of APAP at an optimal condition of 200 mg L−1 catalyst dosage and 0.4 mM PAA concentration at pH 7. The degradation mechanism was elucidated, revealing that superoxide anion (O2•−) played a dominant role, while singlet oxygen (1O2) and alkoxyl radicals (R–O•) also contributed significantly. The degradation pathways of APAP were proposed based on LC-MS analyses and molecular electrostatic potential calculations, identifying three primary routes of transformation. Stability tests confirmed that the ZIF-67@KSB3 catalyst retained an 86% efficiency in APAP removal after five successive cycles, underscoring its durability and potential for application in pharmaceutical wastewater treatment.

Structural simulation and performance evaluation of a novel synthesized ZIF in the adsorption of MO from aqueous solutions.

Zeolitic imidazolate frameworks (ZIFs) are desirable materials widely applied as adsorbent for wastewater treatment. This study synthesizes and applies a novel structured ZIF with organic ligand of 2-methyl imidazole and metal salt of copper (II) sulfate as adsorbent. Its morphology and structure were investigated using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, field emission scanning electron microscope, energy dispersive X-ray spectrometry, and mapping analysis. After structural analysis, the adsorbent structure was simulated and determined using Avogadro and Gaussian software. The removal efficiency of prepared ZIF in the removal of methyl orange from aqueous solution was evaluated. The effect of pH, the concentration of the dye in solution, dosage of the adsorbent, and the contact time between adsorbent and solution on the methyl orange removal were examined using central composite design of response surface methodology in five levels. The maximum dye removal of 99% was obtained for 2g adsorbent/L, pH of 3.3, and initial dye concentration of 121mg/L after 127min contact time. In addition, to reduce the economic costs and energy consumption, the synthesis time was also reduced and used to show the applicability of the adsorbent prepared and understand its advantages and disadvantages in removing methyl orange dye from aqueous solutions. This molecular adsorbent is stable, and it can be stored for months. On the other hand, this ZIF can be easily recovered and reused many times. In this research, after five times of recovery, there was no significant change in the effectiveness of the adsorbent.

Improving the hydrostability of zeolitic imidazolate framework coatings using a facile silk fibroin protein modification method

Zeolitic imidazolate frameworks (ZIFs) are an important subclass of metal-organic frameworks (MOFs) with zeolite-type topology, which can be fabricated under ambient synthesis conditions. However, the applications of ZIFs are commonly limited due to the weak hydrostability of their metal–ligand coordination bonds, particularly under humid and aqueous conditions. In this work, as an example, the hydrolysis behaviours of ZIF-L with a special focus on ZIF-L coatings were tested at aqueous conditions with a wide range of pHs to systematically study and fundamentally understand their structural stability and degradation mechanism. Pristine ZIF-L powder and ZIF-L coatings were severely damaged after only 24 h in aqueous media. Interestingly, the ZIF-L coatings showed two distinct hydrolyzation pathways regardless of pH conditions, exhibiting either a ring-shaped etching or unfolding behaviours. While the ZIF-L powders were hydrolyzed almost identically across all pH conditions. With this new understanding, a facile silk fibroin (SF) protein modification method was developed to enhance the hydrostability of ZIF-L coatings in aqueous media. The effect of protein concentration on surface coating was systemically studied. ZIF-L coating retained its surface morphology after soaking in water and demonstrated switchable super wetting properties and superior separation performance for oil/water mixture. As a result, the quick SF protein modification significantly enhanced the stability of ZIF-L coatings under various pHs, while retaining their switchable wetting property and excellent separation performance.

Construction of two-dimensional thick sheet-like carbide and Co nanocrystals heterostructure toward efficient electromagnetic wave absorption

Deeply studied the electromagnetic wave absorption (EWA) mechanism of Mo2C heterostructure is crucial for realizing the application of Mo2C-based materials in new multifunctional integrated microwave absorbing coatings. In order to exclude the influence of special three-dimensional morphology (spherical, hollow, etc) on EWA performance, we designed the two-dimensional (2D) thick sheet-like Mo2C/Co@NC heterostructure that composed of molybdenum carbide (Mo2C), cobalt (Co) nanoparticles and nitrogen-doped carbon (NC), derived from the MoO42− substituted 2D sheet-like Co zeolite imidazolate frameworks (Mo/Co BIFs). The Mo2C/Co@NC has better EWA performance than Co@NC and Mo2C@NC. In the thickness range of 2∼4 mm, the effective absorption bandwidth can cover up to 10.5 GHz, and the strongest absorption can reach −48 dB. Behind the excellent EWA performance, multiple polarization relaxation and enhanced interface polarization are acting together. Moreover, the structure and interface effects of Mo2C/Co heterojunction are also revealed by DFT calculation. This work provides a workable methodology for manipulating the heterogeneous interface of MOFs-derived Mo2C based material and understanding the EWA mechanism of Mo2C-based heterostructure.

Surface Modification of Hydroxyapatite Coating for Enhanced Antibiotic Therapy

A major strategy to combat implant-associated infections is to develop implant coatings with intrinsic antibacterial activity. Since hydroxyapatite (HAp) coatings and antibiotic administration are commonly used in clinical settings, developing HAp-coated implants with localized antibiotic-releasing properties has attracted popularity. Considering the antibacterial metal species (Ag, Zn, Cu, etc.) in metal–organic frameworks and their drug delivery capacity, in this study, a gentamicin-loaded zeolitic imidazolate framework-8 nanolayer was deposited on a plasma-sprayed HAp coating (HAp/ZIF-8@Gent), which served as a Gent and Zn2+ reservoir. The investigation on the binding interaction between ZIF-8 and HAp indicated that the growth of ZIF-8 was through a Zn2+ seed layer on the HAp coating via an adsorption–replacement mechanism, instead of simple physical adsorption. The HAp/ZIF-8@Gent coating exhibited a sustained drug-release property, and the cumulative concentration of released Gent reached 239.8 ± 7.1 μg/mL on day 8. Compared to the HAp-Zn and HAp/ZIF-8 coatings, the HAp/ZIF-8@Gent coating exhibited significantly higher antibacterial activity against E. coli. This was ascribed to the combined antibacterial effects of Zn2+ and Gent. The cytocompatibility of the HAp/ZIF-8@Gent coating was confirmed via cell proliferation. Above all, the ZIF-8-modified HAp coating with localized delivery of Gent and Zn2+ possessed excellent antibacterial activity and acceptable cytocompatibility, showing potential in mitigating implant-associated infections.

Metal-free N, B, F ternary-doped carbon electrocatalyst for boosting the oxygen reduction reaction and high-performance zinc–air battery

Developing efficient metal-free carbon-based electrocatalysts for the oxygen reduction reaction (ORR) is significant and challenging to reduce the cost of fuel cells and metal–air batteries for large-scale applications. Herein, a novel metal-free N, B, F ternary-doped carbon electrocatalyst (FBNCΔ(1:6)-950) exhibited an excellent ORR performance with half-wave potential of 0.858 V vs. reversible hydrogen electrode (RHE) via an almost exclusively four-electron transfer pathway in 0.1 M KOH, even better than the commercial Pt/C (20 %). Moreover, the FBNCΔ(1:6)-950-based zinc–air battery (ZAB) shown an excellent power density of 147 mW·cm−2 and long-term stability of 100 h. The FBNCΔ(1:6)-950 was constructed via pyrolyzing zeolite imidazole framework (ZIF-8) precursor containing BF4– at 950 °C under N2 to volatilize the Zn. According to the structural characterization and theoretical calculations, B and F from BF4– not only increased the number of active sites of pyridine-N by etching intact carbon matrix, but also co-modified part of pyridine-N to further optimize the electronic structure and reduce the adsorption energy of *OH, both of which together result in the excellent performance of FBNCΔ(1:6)-950. This work provides a fresh perspective on the advancement of highly active metal-free carbon-based electrocatalysts for the ORR and ZAB.

CeO2 nanocages with tetra-enzyme mimetic activities for dual-channel ratiometric colorimetric detection of microcystins-LR

BackgroundMicrocystin-leucine-arginine (MC-LR) produced by various cyanobacteria during harmful algal bloom poses serious threats to drinking water safety and human health. Conventional chromatography-based detection methods require expensive instruments and complicated sample pretreatment, limiting their application for on-site detection. Colorimetric aptasensors are simple and rapid, and are amenable to fast detection. However, they provide only one output signal, resulting in poor sensitivity and accuracy. Dual-channel ratiometric colorimetric method based on the peroxidase-like activity of nanozyme can achieve self-calibration by recording two reverse signals, providing significantly enhanced sensitivity and accuracy. ResultsCeO2 nanocages (CeO2 NCs) with tetra-enzyme mimetic activities (oxidase-, peroxidase-, catalase- and superoxide dismutase-like activities) were facilely synthesized using zeolitic imidazolate framework-67 (ZIF-67) as sacrificial template. The peroxidase-like activity of CeO2 NCs can be regulated by DNA, and it showed opposite response to two chromogenic substrates (2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 3,3′,5,5′-tetramethylbenzidine (TMB)), which was mainly attributed to the changed affinity. On the basis of MC-LR aptamer-tunable peroxidase-like activity of CeO2 NCs in TMB and ABTS channel, a dual-channel ratiometric colorimetric aptasensor was constructed for detection of MC-LR. Compared with conventional single-signal colorimetric assays, the proposed method showed lower limit of detection (0.66 pg mL−1) and significantly enhanced sensitivity. Moreover, the practicability of the ratiometric colorimetric assay was demonstrated by detecting MC-LR in real water samples, and satisfactory recoveries (94.9–101.9 %) and low relative standard deviations (1.6–6.3 %) were obtained. SignificanceThis work presents a nanozyme-based ratiometric colorimetric aptasensor for MC-LR detection by recording the reverse responses of two chromogenic reactions. Benefiting from the self-calibration function, the method can achieve higher sensitivity and accuracy. The short detection time and practical application in real water samples show great potential for environmental monitoring.

Investigating and improving the water stability of ZIF-L-Co for electrochemical glucose sensors

More and more studies have shown that zeolitic imidazolate framework (ZIF) materials exhibit very high thermal stability, but poor aqueous stability, that limits their practical application. In this work, leaf-shaped ZIF-67 on the surface of foam nickel (namely as ZIF-L-Co/NF) is selected to deeply investigate the mechanism of water stability. The related reaction process of ZIF-L-Co/NF in water is proposed for the first time and demonstrated based on a series of characterizations. The results show that ZIF-L-Co/NF lost its skeleton after only 1 h in water, and completely converted into cobalt hydroxide (Co(OH)2) after 24 h. The reaction process is proved to be invertible via designed experiments. Considering invertible reaction, two strategies are proposed to improve the water stability of ZIF-L-Co, by (1) introducing second metal center Zn and (2) adding extra 2-methylimidazole (Hmim) to push the reaction process in reverse. Based on the above improving strategies, bimetallic ZIF-L-CoZn/NF(2:1) prepared by introducing the second metal Zn is applied as electrochemical sensor towards glucose, and exhibits high sensing performance with good sensitivity, selectivity, and wide detection range as glucose sensor. Experimental results demonstrate its excellent aqueous stability. This work provides a totally new viewpoint for the application of ZIF materials in aqueous conditions and perfects the characteristics of ZIF family.

FeFe]-Hydrogenase Encapsulated in Zeolitic Imidazolate Framework (ZIF)-8 Nanoparticles as a Robust Biocatalyst for Photocatalytic Hydrogen Production

FeFe]-Hydrogenase Encapsulated in Zeolitic Imidazolate Framework (ZIF)-8 Nanoparticles as a Robust Biocatalyst for Photocatalytic Hydrogen Production

Popping and Locking: Balanced Rigidity and Porosity of Zeolitic Imidazolate Frameworks for High-Productivity Methane Purification.

Zeolitic imidazolate frameworks (ZIFs) hold great promise in carbon capture, owing to their structural designability and functional porosity. However, intrinsic linker dynamics limit their pressure-swing adsorption application to biogas upgrading and methane purification. Recently, a functionality-locking strategy has shown feasibility in suppressing such dynamics. Still, a trade-off between structural rigidity and uptake capacity remains a key challenge for optimizing their high-pressure CO2/CH4 separation performance. Here, we report a sequential structural locking (SSL) strategy for enhancing the CO2 capture capacity and CH4 purification productivity in dynamic ZIFs (dynaZIFs). Specifically, we isolated multiple functionality-locked phases, ZIF-78-lt, -ht1, and -ht2, by activation at 50, 160, and 210 °C, respectively. We observed multiple-level locking through gas adsorption and powder X-ray diffraction. We uncovered an SSL mechanism dominated by linker-linker π-π interactions that transit to C-H···O hydrogen bonds with binding energies increasing from -0.64 to -2.77 and -5.72 kcal mol-1, respectively, as evidenced by single-crystal X-ray diffraction and density functional theory calculations. Among them, ZIF-78-ht1 exhibits the highest CO2 capture capacity (up to 18.6 mmol g-1) and CH4 purification productivity (up to 7.6 mmol g-1) at 298 K and 30 bar. These findings provide molecular and energetic insights into leveraging framework flexibility through the SSL mechanism to optimize porous materials' separation performance.

Polydopamine-Mediated Metal-Organic Frameworks Modification for Improved Biocompatibility.

Engineered nanomaterials are promising in biomedical application. However, insufficient understanding of their biocompatibility at the cellular and organic levels prevents their widely biomedical applications. Metal-organic frameworks (MOFs) have attracted increasing attention in recent years. In this work, zeolitic imidazolate framework-8 (ZIF-8) and polydopamine (PDA)-modified ZIF-8 are chosen as model nanomaterials due to its emergent role in nanomedicine. In vitro, the results demonstrate that the PDA coating greatly alleviates the cytotoxicity of ZIF-8 to RAW264.7, LO2, and HST6, which represent three different cell types in liver organs. Mechanistically, ZIF-8 entering into the cells can greatly induce the reactive oxygen species generation, which subsequently induces cell cycle delay and autophagy, ultimately leads to enhanced cytotoxicity. Further, human umbilical vein endothelial cells model and zebrafish embryos assay also confirm that PDA can compromise the ZIF-8 toxicity significantly. This study reveals that PDA-coated MOFs nanomaterials show great potential in nano-based drug delivery systems .

Development of a Molecular Dynamics Model to Assess the Possibility of Type II/III Porous Liquid Formation

The study of porous liquids (PLs) using molecular dynamics (MD) simulation is one of the most interesting and attractive research topics. The possibility of creating permanent porosity in a solvent and increasing its adsorption capacity is very practical. The purpose of the present study is to examine how an MD model can be developed to evaluate the possibility of PL formation. Additionally, the validation of the model was conducted by simulations using two metal–organic frameworks (MOFs) including zeolitic imidazolate framework-8 (ZIF-8) and Hong Kong University of Science and Technology-1 (HKUST-1) as porogens and water (H2O) and triethylene glycol (TEG) as solvents. The results revealed that H2O and TEG are incapable of penetrating the ZIF-8 pores due to their small size and unfavorable thermodynamics; however, both solvents easily penetrate through the large HKUST-1 pores. These observations aligned with findings from experimental literature studies, thus confirming the validity of the model. In order to expand the model’s scope, the developed model was used to assess the possibility of PL formation using ZIF-8 and HKUST-1 with different pore and window sizes and shapes, and a wide range of hydrocarbon liquids with different molecular sizes and shapes as solvents. It was found that ZIF-8 can form PLs with a more extensive range of sterically hindered solvents due to its smaller apertures and incompatible shape. In addition, only a few solvents (e.g., n-pentane, benzene, 1,3,5-trimethylbenzene, 1,3,5-triisopropylcyclohexane, and 1,3,5-triisopropylbenzene) can partially penetrate its ZIF-8 pores without steric hindrance. These privileged solvents typically have an aspect ratio far from 1, indicating a more elongated shape, and/or more linear branches. In contrast, HKUST-1, which has larger apertures and a compatible shape, allows for complete penetration of specific solvents (e.g., benzene, iso-octane, n-pentane), thereby preventing PL formation with such combinations. In addition, cyclohexane has the ability to partially penetrate the pores of HKUST-1. Therefore, in addition to the size of the solvent molecule, one of the most important properties for penetration is the compatibility of the shape of the porogen pore window with the shape of the solvent molecule. This research provides important new information on how PLs come to be by illuminating the role that solvent molecules and porogen play in promoting penetration and, in the end, impacting the process of PL formation.

Drug delivery system based on metal-organic framework improved 5-Fluorouracil against spring viremia of carp virus

Spring viremia of carp virus (SVCV), as a high pathogenicity pathogen, has seriously restricts the healthy and sustainable development of cyprinid farming industry. In this study, we selected 5-Fluorouracil (5-Fu) as the drug model based on zeolitic imidazolate framework-8 (ZIF-8) to construct a drug delivery system (5-Fu@ZIF-8), and the anti-SVCV activity was detected in vitro and in vivo. The results showed 5-Fu@ZIF-8 was uniform cubic particle with truncated angle and smooth surface, and the particle size was 90 nm. The anti-SVCV activity in vitro results showed that the highest inhibition rate of 5-Fu was 77.93% at 40 mg/L and the inhibitory concentration at half-maximal activity (IC50) was 20.86 mg/L. For 5-Fu@ZIF-8, the highest inhibition rate was 91.36% at 16 mg/L, and the IC50 value was 5.85 mg/L. In addition, the cell viability was increased by 18.1% after 5-Fu treatment. Similarly, after 5-Fu@ZIF-8 treatment, the cell viability increased by 27.3%. Correspondingly, in vivo experimental results showed the viral loads reduced by 18.1% on the days 7 and the survival rate increased to 19.4% at 80 mg/L after 5-Fu treatment. For 5-Fu@ZIF-8, the viral loads reduced by 41.2% and the survival rate increased to 54.8%. Mechanistically, 5-Fu inhibits viral replication by regulating p53 expression and promoting early apoptosis in infected cells. All results indicated that 5-Fu@ZIF-8 improved the anti-SVCV activity; it may be a potential strategy to construct a drug-loaded system with ZIF-8 as a carrier for the prevention and treatment of aquatic diseases.

In Situ-Derived N-Doped ZnO from ZIF-8 for Enhanced Ethanol Sensing in ZnO/MEMS Devices.

Microelectromechanical systems (MEMS) gas sensors have numerous advantages such as compact size, low power consumption, ease of integration, etc., while encountering challenges in sensitivity and high resistance because of their low sintering temperature. This work utilizes the in situ growth of Zeolitic Imidazolate Framework-8 (ZIF-8) followed by its conversion to N-doped ZnO. The results obtained from scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicate that the in situ derivation of ZIF-8 facilitates the adhesion of ZnO particles, forming an island-like structure and significantly reducing the interfaces between these particles. Furthermore, powder X-ray diffraction (XRD) analysis, elemental mapping, and X-ray photoelectron spectroscopy (XPS) analysis confirm the conversion of ZIF-8 to ZnO, the successful incorporation of N atoms into the ZnO lattice, and the creation of more oxygen vacancies. The ZIF-8-derived N-doped ZnO/MEMS sensor (ZIF (3)-ZnO/MEMS) exhibits remarkable gas sensitivity for ethanol detection. At an operating temperature of 290 °C, it delivers a substantial response value of 80 towards 25 ppm ethanol, a 13-fold enhancement compared with pristine ZnO/MEMS sensors. The sensor also exhibits an ultra-low theoretical detection limit of 11.5 ppb to ethanol, showcasing its excellent selectivity. The enhanced performance is attributed to the incorporation of N-doped ZnO, which generates abundant oxygen vacancies on the sensor's surface, leading to enhanced interaction with ethanol molecules. Additionally, a substantial two-order-of-magnitude decrease in the resistance of the gas-sensitive film is observed. Overall, this study provides valuable insights into the design and fabrication strategies applicable to high-performance MEMS gas sensors in a broader range of gas sensing.

Superior supercapacitor performance with tuneable 2D/3D morphological microporous carbons of zeolitic imidazolate frameworks synthesized by recycling mother liquors

Carbonized metal–organic frameworks (MOFs)-based nanoporous carbon materials (NPCs) offer attractive activities in electrochemical energy conversion and storage (EECS) applications; however, there is the need for scalable MOFs production under reduced energy/environmental impact. This study reports a green synthesis route for model zeolitic imidazolate framework (ZIF-8) materials via recycling methanol-based mother liquors (ZIF-RMLx) under room temperature stirring and their carbonized materials (CZC-RMLx) for high-performance supercapacitors. Series of ZIF-RMLx samples produced in four recycles offer rod-/sheet-/polyhedral-like 2D/3D microstructures with tuneable internal and external framework and morphological features. Accordingly, CZC-RMLx, obtained by direct pyrolysis, with high microporosity and surface area of 1500 m2 g−1 deliver excellent capacitance values of 200–340 F g−1, compared to typical MOFs-derived or chemically activated/templated NPCs, produced via extended chemical processing. Structure-relevant and comparative performance analysis reveal insights for improved charge storage and carbonization-dependent graphitization, nitrogen-doping and microporosity-controlled capacitance characteristics in the CZC-RMLx over typical NPCs in literature. The device-level performance with a long-term durability over 21,000 cycles is demonstrated. The practical potential of CZC-RMLx is further evaluated by fabricating solid-state cells and their parallel and series circuit combinations result in overall capacitance and voltage boost to 450 F g−1 and 2.4 V, respectively.

Facile construction of gefitinib-loaded zeolitic imidazolate framework nanocomposites for the treatment of different lung cancer cells.

Gefitinib (GET) is a revolutionary targeted treatment inhibiting the epidermal growth factor receptor's tyrosine kinase action by competitively inhibiting the ATP binding site. In preclinical trials, several lung cancer cell lines and xenografts have demonstrated potential activity with GET. Response rates neared 25% in preclinical trials for non-small cell lung cancer. Here, we describe the one-pot synthesis of GET@ZIF-8 nanocomposites (NCs) in pure water, encapsulating zeolitic imidazolate framework 8 (ZIF-8). This method developed NCs with consistent morphology and a loading efficiency of 9%, resulting in a loading capacity of 20wt%. Cell proliferation assay assessed the anticancer effect of GET@ZIF-8 NCs on A549 and H1299 cells. The different biochemical staining (Calcein-AM and PI and 4',6-Diamidino-2-phenylindole nuclear staining) assays assessed the cell death and morphological examination. Additionally, the mode of apoptosis was evaluated by mitochondrial membrane potential (∆ψm) and reactive oxygen species. Therefore, the study concludes that GET@ZIF-8 NCs are pledged to treat lung cancer cells.

Zeolitic imidazolate framework-8: a versatile nanoplatform for tissue regeneration.

Extensive research on zeolitic imidazolate framework (ZIF-8) and its derivatives has highlighted their unique properties in nanomedicine. ZIF-8 exhibits advantages such as pH-responsive dissolution, easy surface functionalization, and efficient drug loading, making it an ideal nanosystem for intelligent drug delivery and phototherapy. These characteristics have sparked significant interest in its potential applications in tissue regeneration, particularly in bone, skin, and nerve regeneration. This review provides a comprehensive assessment of ZIF-8's feasibility in tissue engineering, encompassing material synthesis, performance testing, and the development of multifunctional nanosystems. Furthermore, the latest advancements in the field, as well as potential limitations and future prospects, are discussed. Overall, this review emphasizes the latest developments in ZIF-8 in tissue engineering and highlights the potential of its multifunctional nanoplatforms for effective complex tissue repair.

Interface Engineering of MOF-Derived Co3O4@CNT and CoS2@CNT Anodes with Long Cycle Life and High-Rate Properties in Lithium/Sodium-Ion Batteries.

Metal-organic framework materials can be converted into carbon-based nanoporous materials by pyrolysis, which have a wide range of applications in energy storage. Here, we design special interface engineering to combine the carbon skeleton and nitrogen-doped carbon nanotubes (CNTs) with the transition metal compounds (TMCs) well, which mitigates the bulk effect of the TMCs and improves the conductivity of the electrodes. Zeolitic imidazolate framework-67 is used as a precursor to form a carbon skeleton and a large number of nitrogen-doped CNTs by pyrolysis followed by the in situ formation of Co3O4 and CoS2, and finally, Co3O4@CNTs and CoS2@CNTs are synthesized. The obtained anode electrodes exhibit a long cycle life and high-rate properties. In lithium-ion batteries (LIBs), Co3O4@CNTs have a high capacity of 581 mAh g-1 at a high current of 5 A g-1, and their reversible capacity is still 1037.6 mAh g-1 after 200 cycles at 1 A g-1. In sodium-ion batteries (SIBs), CoS2@CNTs have a capacity of 859.9 mAh g-1 at 0.1 A g-1 and can be retained at 801.2 mAh g-1 after 50 cycles. The unique interface engineering and excellent electrochemical properties make them ideal anode materials for high-rate, long-life LIBs and SIBs.

Zeolitic imidazolate framework (ZIF) derived MoS2/Co3S4/NPC as the supercapacitor electrode material

Here in, we report the synthesis of a ZIF-67-based Molybdenum disulfide composite and analyze the structural and electrochemical properties of the material. A class of zeolitic imidazole framework ZIF-67 (Co) was first synthesized and annealed in a reducing (Ar/H2) environment. To form Co/NPC (Nano-porous Carbon). Then different masses of Co/NPC were added during the hydrothermal preparation of MoS2 to check the effect of Co/NPC while the amounts of Mo and S were kept constant. Three samples with different mass ratios CMS-1 (Mo1:Co/NPC0.5), CMS-2 (Mo1:Co/NPC1), CMS-3 (Mo1:Co/NPC2) were prepared. XRD analysis confirmed the formation of MoS2/Co3S4/NPC composite. Electrochemical measurement showed a high specific capacitance of 612F g−1 for the sample having equal mass ratio of Mo and Co/NPC i.e. CMS-2. The incorporation of Co/NPC significantly improved the electrochemical properties of MoS2. The material also showed a high cyclic stability of 88.59 % after 9000 cycles. Among the three samples, the Mo1:Co/NPC1 /CMS-2 showed the best performance hence proving to be the optimum ratio.

Preparation of Ni, Co doped hollow carbon nanocage from core-shell structure ZIF-8@ZIF-67 for nitrobenzene monitoring

Herein, we employed a Ni, Co duplex metal-doped hollow carbon nanocage derived from the core-shell Zeolite imidazole framework-8 (Zn)@Zeolite imidazole framework-67 (Co) (ZIF-8@ZIF-67) for the sensitive electrochemical detection of nitrobenzene (NB). The precursor was created by coating ZIF-67 on the surface of ZIF-8 through the epitaxial growth method, followed by Ni doping. Subsequent pyrolysis resulted in the formation of a Ni, Co duplex metal-doped hollow carbon nanocage. Characterization of the nanocomposite confirmed the unique hollow and porous structure of NiCo/C, maintaining a dodecahedral morphology with a uniform distribution of carbon and transition metal nanoparticles. The NiCo/C-modified electrode exhibits a wide linear dynamic range (0.05–11.22 μM and 11.22–230.06 μM), a lower limit of detection (0.14 μM), superior stability and selectivity for the detection of NB. Moreover, it shows appropriate practicality toward detecting NB in natural water samples.