Metal-organic Frameworks Research Articles

Boosting CO2 separation in porphyrinic MOF-based mixed matrix membranes via central metal atom integration

As atmospheric CO2 levels continue to rise, contributing to the climate crisis, there is an increasing urgency to separate this gas from others and to expedite related research. Metal-Organic Frameworks (MOFs), known for their porosity and tunability, have already made significant impacts in this field, particularly to be used as part of a membrane material. This study introduces a novel method to enhance the CO2 separation capabilities of MOFs-based mixed matrix membranes (MMMs). Instead of taking the traditional approach by functionalizing the MOF's ligands or varying the metal or metal-oxo MOF nodes, we harness the properties of metal atoms by integrating them as central elements within porphyrinic MOF linkers through a simple post-metalation method. As a result, by incorporating the post-metalated MOF-525 as fillers into the 6FDA-DAM (6FDA: 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride; DAM: 2,4,6-trimethyl-1,3-diaminobenzene) polymer to fabricate MMMs, we effectively demonstrate improved CO2/N2 and CO2/CH4 gas separation capabilities of around 20 % without the necessity to use a very high MOF loading (only 2 wt%). Further analysis on the gas transport reveals that such a performance improvement mainly comes from the enhanced CO2 solubility, which might be attributed to the presence of the metal atoms in the post-metalated MOF 525. Lastly, in order to get a more comprehensive understanding, we also carry out a computational study as a tool to validate and predict the experimental results of our MMMs. This study then opens up the possibility to further investigate the efficacy of introducing various metal atoms in other porphyrinic MOFs when they are used as fillers to significantly boost the CO2 separation performance of MMMs.

Constructing highly durable proton transport channels in polybenzimidazole membranes using highly stable porous carbonized metal organic frameworks

The use of porous materials to construct proton transport channels in high-temperature proton exchange membranes (HT-PEMs) is an effective strategy for improving cell performance. However, most reported metal organic frameworks (MOFs) struggle to maintain stability in highly acidic or alkaline environments, which hinders their application. In this work, highly stable carbonized MOFs based on MIL-101(Cr) are prepared and used as porous materials to construct proton transport channels in HT-PEMs. The porous carbon derived from MOFs exhibits new structures and properties owing to the periodic porous and hybrid structure used to prepare porous carbon with uniform pores. High specific surface area and highly stable proton transport channels are constructed in a phosphoric acid (PA)-doped polybenzimidazole system. The tensile properties and anti-oxidization capacity of prepared membranes are improved as the doping content of carbonized MOFs increased. Meanwhile, the conductivities of prepared membranes increase with increasing amounts of the carbonized MOFs at a similar acid doping level. The membrane noted CM15@OPBI achieves a conductivity of 0.059 S cm-1 and a power density of 648 mW cm-2 at 0% RH, 160 °C (H2/O2). Moreover, the membrane stably withstands a constant current discharge of 200 mA cm−2 for 200 h under those conditions.

Synthesis and characterization of a copper-based metal–organic framework and its application in microextraction and determination of chlorpyrifos by ion mobility spectrometry

This study describes an innovative method for the microextraction and determination of chlorpyrifos, utilizing a newly synthesized copper-based metal–organic framework (MOF) with 3,3ʹ-thiodipropionic acid as the ligand. This approach offers a sensitive and reliable solution for the ultra-trace determination of chlorpyrifos in various matrices, highlighting its potential for broader environmental and food safety applications. To minimize environmental impact, a hydrothermal method was chosen for MOF synthesis. The MOF was fully characterized using FT-IR, X-ray diffraction, FESEM-EDX, BET, zeta potential analysis, and XPS; and integrated into a dispersive solid-phase microextraction (DSPME) technique, paired with ion mobility spectrometry (IMS) for chlorpyrifos detection. The DSPME procedure has been optimized for extraction efficiency, minimal solvent use, and low absorbent consumption. A low detection limit of 0.65 ng mL−1 was observed and validated along with a linear detection range of 1.0–400.0 ng mL−1 as the result of this optimization. Experiments with water, pear fruit, and soil samples demonstrated the method’s practicality and superior performance compared to existing techniques, showcasing its potential for real-world applications.

Scalable MOF-based mixed matrix membranes with enhanced permeation processes facilitate the scale application of membrane-based carbon capture technologies

Mixed-matrix membranes (MMMs) leverage the processability of polymers and selectivity of Metal-Organic Frameworks (MOFs). However, they still suffer from poor interfacial compatibility and limited scalability in preparation. In certain polymers, MOFs can bridge the pores within the polymer membrane, enhancing the CO2 adsorption and solubility properties, thus selectively boosting the CO2 permeability. In this study, high-performance MMMs were prepared using scalable CALF-20 in combination with PIM-1. MMMs with a 5% doping level achieved CO2 permeability up to 8003 barrer with 25% improvement in CO2/N2 selectivity. This enhancement was attributed to well-designed MMMs, where MOFs matched the abundant non-interconnecting pores in the PIM-1 membrane. This study represents a significant advancement towards scaling up the preparation of high-performance MOF-based MMMs for carbon capture applications.

In Situ Synthesis of Metal-Organic Frameworks on Sulfonated Cellulose Nanofibrils

The intrinsic fragility and inferior processibility of metal-organic frameworks (MOFs) particles often restrict their functional application despite their high surface area and porous structure. We investigated the feasibility of sulfonated cellulose nanofibrils (SCNF) as a biopolymer and template to hybridize MOFs. SCNF was synthesized through periodate oxidation followed by bisulfite sulfonation and characterized using solution-state NMR spectra. The sulfonate groups increased electronegativity and enhanced the dispersibility of the cellulose fibers. More importantly, the negatively charged sulfonates could be manipulated as anchors for metal ions to initiate the in situ growth of MOFs along the surface of cellulose fibers. We have achieved the synthesis of three types of SCNF/MOF hybrids, namely, SCNF/ZIF-8, SCNF/ZIF-67, and SCNF/HKUST-1. These hybrids can be formed as free-standing aerogels, exhibiting remarkably high surface areas and flexibility for applications. The assessment of the adsorptive efficiency of the SCNF/ZIF-8 hybrid indicates that the hybrid material exhibited a notably higher adsorption capacity for methylene blue versus the SCNF control. DFT computational calculation provides further insights into the underlying adsorption mechanisms, revealing that the sulfonates on the SCNF and the nitrogen atoms in the ZIF-8 ligands primarily contributed to the affinity for methylene blue. SCNF offers a versatile and robust biopolymer substrate for templating a wide array of MOFs with promising applications as adsorbents and beyond.

Engineering cellulose aerogel composites for mercury ion sequestration and aquatic real time monitoring based on the immobilization of metal-organic frameworks.

Industrial wastewater effluents containing elevated levels of mercury are a significant menace to both the ecosystem and human health. Despite the advent of metal-organic frameworks (MOFs) as promising adsorbents, their application in treatment of industrial wastewater has been impeded by the challenges associated with handling their powdered form. In this work, we introduce a straightforward method for fabricating MOF composite cellulose aerogels (5MM-101@CA). The resulting adsorbent showed a high adsorption capacity of 409.84 mg/g for Hg (II), with over 75 % removal efficiency maintained after five consecutive adsorption-desorption cycles. Furthermore, the material exhibited high sensitivity for the real-time detection of Hg (II), with a detection limit as low as 6.89×10-8 M. The adsorbent also showed remarkable fluorescence stability for up to a week, indicative of its excellent optical performance. Dynamic adsorption demonstrated the adsorbent's ability to sustain continuous and stable system operation without compromising adsorption efficiency. These findings underscore the effectiveness of post-synthetic modification (PSM) technology in enhancing the performance of MOFs, while highlighting the utility of low-cost cellulose as an effective carrier. Thus, the composite material developed in this work is promising as it not only maximizes the adsorption capabilities of MOFs but also circumvents the risk of secondary pollution.

A newly NH2-UiO-66 composite functionalized by molecularly imprinted polymer for selective and rapid removal of sulfamethoxazole

Metal–organic frameworks (MOFs) are used as novel adsorption materials owing to their large surface area and tunable pore size. However, the lack of selectivity considerably limits their application. Consequently, designing functionalized MOFs with specific recognition abilities is essential for enhancing their adsorption performance. Herein, we synthesized a functionalized NH2-UiO-66 composite modified by molecularly imprinted polymers (MIP@NH2-UiO-66) via a one-step polymerization process in which NH2-UiO-66 and MIP were formed simultaneously. Results demonstrate that MIP@NH2-UiO-66 effectively recognized sulfamethoxazole (SMX) in complex matrices. The adsorption equilibrium was reached in only 30 min, and this fast SMX adsorption on MIP@NH2-UiO-66 was described by the Avrami kinetic model, which indicates a spontaneous and exothermic adsorption process. Within the pH range of 3.0–10.0, MIP@NH2-UiO-66 exhibited an optimal binding capacity for SMX, and the maximum adsorption of SMX was 68.36 mg g−1 at 25°C, which exceeded those of existing adsorption materials (< 60.10 mg g−1). Additionally, MIP@NH2-UiO-66 was regenerated for ∼17 cycles compared to less than eight cycles for the other adsorbents. MIP@NH2-UiO-66 effectively removed 90.58%–99.60% of SMX from river water, rainwater, soil, sediment, chicken, pork, and milk samples, with a relative standard deviation of less than 4.43%. The superior adsorption of SMX on MIP@NH2-UiO-66 was primarily driven by the synergistic effects of the imprinting sites, hydrogen bonding, and electrostatic forces. The one-step polymerization method substantially simplified the synthesis process and reduced the costs, which are promising factors for the synthesis of MOFs with high selectivity.

Facile synthesis of ZnFe2O4/ZnO/Fe3O4/Fe3N/C composites derived from bimetallic MOFs for efficient electromagnetic wave absorption

A novel metal–organic framework (MOF), ZnFe-MOF, was synthesized using a water phase method. By employing an explosion method with ZnFe-MOF as a precursor, a porous carbon composite electromagnetic wave-absorbing powder, ZnFe2O4/ZnO/Fe3O4/Fe3N/Fe2N/Zn/C (ZFC280), was obtained. This study examined the effects of paraffin filling amount and calcination temperature on the absorption performance of carbon composite materials. Notably, when the mass ratio of the absorber to paraffin was 1:1, the nanocomposite absorber ZnFe2O4/ZnO/Fe3O4/Fe3N/C (ZFC300) exhibited superior electromagnetic wave absorption capability. The ZFC300 sample demonstrated nearly complete absorption of electromagnetic waves across frequencies from 2 to 18 GHz with thicknesses ranging from 1 to 10 mm. Particularly, ZFC300 achieved a minimum reflection loss of −55.32 dB at 4.31 GHz with the 5.46 mm thickness and exhibited the broadest absorption bandwidth of 4.14 GHz at a thickness of 2.0 mm. The primary loss mechanism of the multicomponent and porous ZFC300 was dielectric loss with supplementary magnetic loss. Owing to its excellent absorption performance, the ZFC300 absorber is be a promising candidate for both civilian and military applications.

Ternary metal oxide carbon composite as high-performance electrode material for supercapacitor applications

Recently, ternary metal oxides carbon composites recognized as metal organic frameworks (MOFs) have gained striking attention for supercapacitor electrode material due to high surface area, porosity, chemical stability, tunable properties, redox activity, and eco-friendly material. ZIF-67 is a novel MOF possessing these characteristics. Therefore, the present work reports the development of ternary iron-nickel–cobalt ZIF-67 composites (FeNiCo ZIF-67) using co-precipitation method with the variation in molar concentration of iron oxide, nickel oxide, and cobalt oxide. Physico-chemical characterizations of developed materials were investigated through X-ray diffraction (XRD), Raman spectroscopy, energy dispersive X-ray (EDX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) to confirm the successful formation of composites and structure, morphology. Then, the electrodes were fabricated for all three synthesized composites and electrochemical analyses such as cyclic voltammetry (CV), galvanic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) were performed. The results revealed the porous polyhedral structure of FeNiCo ZIF-67 with different compositions consisting of interconnected nanoparticles played an important role in increasing the charge storage capacity of the material. Among the composites, FeNiCo ZIF-67 (1:2:1) electrode material achieved the highest specific capacitance of 532.7 F/g at a current density of 1 A/g. FeNiCo ZIF-67 (1:2:1) exhibited maximum electrochemical active surface area 89.12. Electrochemical impedance spectroscopy (EIS) demonstrated the minimal resistance of 7.8 Ω by FeNiCo ZIF-67 (1:2:1) composite electrode compared to the other two electrode materials. Cyclic stability study revealed the capacitance retention of 91 % after 10,000 continuous charge discharge cycles at a current density of 10 A/g. Electrode material demonstrated an outstanding electrochemical performance, and this work could provide a simple strategy to fabricate FeNiCo ZIF-67 nanostructured electrode materials for supercapacitors.

Synthesis and characterization of novel magnetic metal organic framework for efficient removal of ketoprofen from aqueous solutions: Mechanism of interaction, adsorption and optimization via BOX-Behnken design

This investigation examines the adsorption and elimination of the anti-inflammatory medication ketoprofen (KTP) in relation to a newly developed magnetic thorium metal-organic framework (MTh-MOF). The study found that KTP absorption on MTh-MOF resulted in a reduction in pore volume, pore size, and surface area, as revealed by N2 adsorption/desorption isotherm analysis used to evaluate the characteristics of the MTh-MOF. Scanning electron microscopy (SEM) showed that the pore radius of MTh-MOF decreased from 1.68 nm to 0.82 nm, demonstrating a consistent and uniform structure. Fourier-transform infrared (FT-IR) spectroscopy was employed to identify the functional groups present in MTh-MOF, while X-ray photoelectron spectroscopy (XPS) was used to confirm the compound's structure. The optimal conditions for achieving a high adsorption capacity were found to be at pH 6 and a MTh-MOF dose of 0.02 g. The results indicated that MTh-MOF displayed a high capacity for absorbing KTP, with the adsorption data fitting well with pseudo-second-order kinetic models and the Langmuir isotherm. The adsorption capacity of MTh-MOF for KTP was determined to be 518 mg/g. The adsorption energy of 28.26 kJ·mol–1 suggested that chemisorption was the predominant mode of adsorption. The process of KTP adsorption on MTh-MOF was observed to be spontaneous, endothermic, and random, as evidenced by the temperature-dependent increases in the thermodynamic parameters (ΔGo, ΔHo, and ΔSo). The adsorption process was optimized using Response Surface Methodology and Box-Behnken design (RSM, BBD). Aromatic rings interact via π-π bonding, while chemisorption involves the development of chemical interactions between the adsorbate and adsorbent. Additionally, electrostatic interactions arise from the attraction or repulsion of charges between the adsorbate and adsorbent, and pore-filling occurs when the adsorbate fills the adsorbent's pores. In order to understand the electrical properties, reactivity, and shape of KTP, density functional theory (DFT) was utilized.

Low-temperature fabrication of metal-organic-frameworks/TiO2 photoanode for flexible dye-sensitized solar cells

Metal-organic frameworks (MOFs) are utilized to integrate with TiO2 to enhance the solar-to-electricity conversion efficiency. The porphyrin-based MOF PCN-222 is the focus of the study. The MOF/TiO2 composite is deposited on a flexible ITO-PEN (polyethylene naphthalate) substrate under low-temperature (<150 °C) conditions. The resulting flexible DSSC demonstrates faster electron diffusion and improved charge carrier separation ability, achieving an efficiency of 4.41 % under 100 mW cm−2, AM 1.5 global illumination. In comparison to the traditional FTO-glass-based DSSC, this type of flexible DSSC shows great potential for application in wearable electronic devices.

UiO-67 metal-organic framework loaded on hardwood biochar for sustainable management of environmental boron contaminations

Boron contamination in water poses significant potential risks to human health and the environment, necessitating the development of efficient, cost-effective, and sustainable remediation technologies. This study introduces a novel composite material combining a zirconium-based metal-organic framework (UiO-67) and a low-cost carbonaceous material (hardwood biochar, BC) with synergetic efficiency to address boron-polluted waters. The UiO-67-biochar (UBC) composite exhibits effective surface chemistry and a remarkably high specific surface area of approximately 881.9m²/g, substantially increasing from the 19.7m²/g of biochar. Our experimental results demonstrate that UBC removed up to 88.5% of boron from 20 ppm polluted water, achieving levels compliant with the WHO standards. The composite also showed excellent reusability, maintaining 95% efficiency over multiple cycles without loss of crystallinity. Life cycle assessment and cost analysis indicate that an optimal MOF to biochar ratio of approximately 60wt% minimises CO2 emissions and costs while maximising the boron removal efficiency. The UiO-67-biochar composites proposed here offers a promising scalable solution for boron contamination and potentially other environmental pollutants, combining the high functionality of UiO-67 with the practical and economic advantages of biochar.

Recent advances in photocatalytic degradation of persistent organic pollutants: Mechanisms, challenges, and modification strategies

Ecosystems and human health are seriously threatened by persistent organic pollutants (POPs), which are hazardous, resistant to environmental degradation, and have the capability of bioaccumulating. The sources, ecological dispersion, and potential adverse impacts of POPs are investigated in this study, which further highlights the urgent need to develop successful remediation technologies. As it can use light energy to promote degradation, photocatalysis is a promising approach among other methods. The review explores many evolved photocatalyst materials, such as those based on nanomaterials, metal-organic frameworks (MOFs), carbon, and hybrids, highlighting their characteristics and functions in the removal of pollutants. Enhancing photocatalytic performance through modification techniques such as surface changes, doping, and co-catalyst insertion is explored. The focus is on the degrading mechanisms specific to POPs and further examines the basic ideas and processes of photocatalysis. Despite its enormous significance, environmental stability, electron-hole pair recombination, and limited light absorption are some of the obstacles that photocatalysis faces. Finally, this analysis calls for novel materials and optimization techniques to overcome existing constraints and enhance the effectiveness of POP removal, highlighting future directions for photocatalyst research.

High-intensive aerogels constructed though in-situ growth of ZIF-8-NH2 on wood for efficient formaldehyde absorption

Metal-organic frameworks (MOFs) are highly advantageous due to their tunable pore size, exceptional thermal and chemical stability, and high specific surface area, making them ideal for applications in formaldehyde adsorption. However, the practical use of powdered MOFs is significantly hindered by their recycling challenges. In this research, wood-based composite aerogels (WAZN-X) were successfully prepared through loading Zeolitic Imidazolate Framework-8-NH2 (ZIF-8-NH2) inside wood aerogels. Ascribing to the elimination of lignin and hemicellulose, the enlarged pore structures of wood aerogels and the potential interactions (e.g., hydrogen bonding and electrostatic attractions) between components promoted the uniformly depositing of ZIF-8-NH2 nanocrystals. The WAZN-X aerogels displayed excellent mechanical strength (e.g., the longitudinal Young’s modulus of 68.57MPa) and promising formaldehyde adsorption performance (e.g., a stable formaldehyde removal rate of 98.11%), and kept commendable reusability (95.98% after 5 cycles). This research provides a new insight for developing high-value functional composite adsorbents for efficient formaldehyde purification.

Molecularly imprinting polymethacrylamide onto Cu-based metal-organic framework as a pH-sensitive core-shell nanocarrier for potential anti-cancer drug delivery.

Surface molecularly imprinted polymers (MIPs) are an efficient and rapidly advancing approach, increasingly being utilized in drug delivery systems (DDSs). This research involved synthesizing a core-shell structure, consisting of a metal-organic framework (MOF) core and a doxorubicin (DOX) imprinted polymethacrylamide shell, prepared via precipitation polymerization method in green media. The resulting MOF@MIP was utilized as a nanocarrier for DOX delivery, exhibiting high drug loading capacity and pH responsiveness delivery. The materials were characterized using different techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), thermal gravimetric analysis (TGA), and zeta potential (ZP). In vitro studies on DOX loading and release demonstrated that a higher amount of DOX was released in a sustained manner under tumor tissue conditions (pH 5, 41 °C) compared to normal physiological conditions (pH 7.4, 37 °C). Additionally, cytotoxicity evaluations revealed significant cytotoxic effects of DOX-loaded MOF@MIP on MCF-7 cells (IC50: 2 μg/mL). Based on these findings, the synthesized MOF@MIP shows promise as a potential candidate for the development of anticancer therapeutic delivery platforms.

Dispersive solid phase extraction of 18 PFAS from environmental water samples using a novel MOF-polymeric monolith composite followed by High-Resolution mass spectrometry analysis

Metal-organic frameworks (MOFs) have been broadly coupled with many pretreatment techniques due to their remarkable attributes including high porosity, significantly increased specific surface area, and chemical stability, but their nanoscale dimensions make their handling challenging. To overcome this, a novel MOF-polymeric monolith composite was synthesized and studied as a novel sorbent material in an analytical technique. A rapid and efficient method for the extraction of a mixture of 18 per- and poly-fluoroalkyl (PFAS) compounds from environmental water samples was established based on MOF-polymeric monolith composite assisted dispersive solid phase extraction (d-SPE). The analytical methodology was carried out with the aid of liquid chromatography tandem high-resolution mass spectrometry. Several parameters influencing the extraction efficiency were comprehensively evaluated and optimized. The optimization was based on two processes: the one-variable-at-a-time approach (OVAT) and the central composite design (CCD). Preliminary studies were conducted and the extraction and elution time, as well as the sample volume were evaluated by adopting OVAT approach. The optimal parameters were found to be 15 min for extraction time, 5 min for the elution time and 10 mL as sample volume. Under the optimum conditions, the sample pH, sorbent amount and eluent volume were all evaluated under the design of experiments (DoE). ANOVA demonstrated the suitability of the suggested model with a p-value of less than 0.05 and various diagnostic tests validate the well-fitting results. The software extracted the optimal conditions which were pH = 7, sorbent amount = 10 mg and eluent volume = 750 μL. The method was subsequently validated with respect to accuracy, linearity detection limits and reproducibility. The proposed method presented recoveries over 70 %, method detection limits 1–46 ng/L and relative standard deviations <20 %. Before the implementation of the method in real samples, the “green” character was evaluated using the ComplexGAPI index, indicating the satisfactorily “green” character of the new MOF-based dSPE-LC-HRMS method. Finally, the efficacy of the method for determining PFASs in four environmental water matrices was tested using several matrices of varying complexity, including wastewater effluent, river water, marine water, and runoff.

Catalytic conversion of woody biomass into monomeric chemicals by a microwave mediated metal-organic-framework 818

Metal-Organic Framework (MOF) materials have been reported that can be efficiently applied for biomass upgrading, however, their utilization on real wood degradation is limited. In this study, Zr- and Cu-ion contained MOF-818 materials were modified by microwave heating to decrease their crystallinity and particle size, consequently, increasing their catalytic activity for wood fiber degradation. The modified MOF-818 catalyst facilitated cellulose conversion into organic acids by microwave heating at 160 ℃, achieving a yield of 42.7%. Additionally, it exhibited the conversion of a lignin β-O-4 dimer into aromatic monomer compounds at 120 ℃, achieving a monomeric conversion yield of 64.4%. Importantly, the modified MOF-818 catalyst also realized the direct conversion of the wood fibers into valuable monomers for the first time by microwave heating at 160 ℃ for 30min, with a yield of 16.3%. However, the drawback of the modified MOF-818 catalyst is that it cannot be reused after the wood degradation, which may be because of the decomposition of the MOF-818 during the biomass conversion reaction. The reaction pathways involved in obtaining the products are also discussed. Overall, this study offers a possible approach for wood conversion into monomeric compounds by MOFs catalysts.

Metal-organic framework self-cleaning membrane enhanced water purification based on collaborative separation and photocatalysis process

The existence of membrane contamination will not only affect the flux and rejection of the membrane, but also greatly reduce the service life of the membrane. Therefore, the coupling of photocatalytic Metal-organic frameworks (MOFs) with separation membrane to prepare catalytic self-cleaning membrane can effectively alleviate membrane pollution and maintain membrane flux and rejection. The challenge of photocatalytic self-cleaning membrane treatment of organic wastewater is how to ensure a stable catalyst load while maintaining a high membrane flux, rejection and cycle life. In this paper, the heterojunction photocatalyst NH2-MIL-125@MIL-88B constructed based on the MOF-on-MOF principle was supported on Polyethersulfone (PES) substrate membrane by vacuum filtration method. Then, polyacrylic acid (PAA) and chitosan (CTS) are adhered to the loading side through a co crosslinking reaction, introducing PAA@CTS layer. The PAA@CTS layer not only improves the load stability of the photocatalyst but also enhances the hydrophilicity of the self-cleaning membrane in collaboration with the photocatalyst. The construction of the self-cleaning membrane further increases its flux without affecting the rejection of the base membrane, breaking the tradeoff between permeability and rejection. The rejection of the best self-cleaning membrane was 96.6%, and the flux was 58.4L·m-2·h-1. In the treatment process of simulated antibiotic wastewater, the flux recovery rate (FRR) of M-2 is as high as 98%, and the irreversible fouling ratio (Rir) is only 1%, which proves its good antifouling properties and stability, and is expected to be used for efficient treatment of antibiotic wastewater.

Solvothermal synthesis of Zr-metal-organic framework/V2C MXene based composite on nickel foam for highly selective detection of epinephrine in simulated blood serum

Metal-organic frameworks (MOFs) combined with MXene materials have recently gained considerable attention for their unique properties, including exceptional structural characteristics and electrical conductivity. These attributes enable them to maintain a high concentration of electroactive sites, making them particularly suitable for electrochemical applications. Here, we demonstrate solvothermal synthesis of Zr-metal–organic framework(Zr-MOF)/V2C MXene composite decorated nickel foam (NF) for electrochemical detection of Epinephrine (EP) in simulated blood serum samples. X-ray diffraction analysis confirms the formation of the cubic structured Zr-MOF/V2C MXene composite. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) reveal the existence of numerous rectangular sheets and nanospheres of the composite. Utilizing the differential pulse voltammetry (DPV) technique, the sensor demonstrates a remarkable sensitivity of 19 µA/µM.cm−2 to EP within a wide linear detection range from 1 µM to 1 mM with a lower limit of detection of 0.86 µM (=3 S/m). The fabricated sensor exhibits high selectivity against interfering species like uric acid (UA), ascorbic acid (AA), glucose (GLU), urea, etc. Real-sample analysis conducted in simulated blood samples using the standard addition method showcases an outstanding recovery percentage of approximately 100 %. Zr-MOF/V2C MXene composite, with its conductive nature and high surface area, forms a robust interaction with EP, leading to a significant alteration in the sensor’s electrical properties. Meanwhile, the porous NF substrate is crucial in maintaining stability, boosting catalytic activity by offering numerous active sites, and enabling swift electron transfer. Affirming the efficacy of the Zr-MOF/V2C MXene composite, herein, as an exceptional electrode with high performance. The composite shows significant promise in detecting various biomolecules essential for biomedical research applications.

Organic-inorganic hybrids cathode with Hydrogen Bonding Network for highly efficient zinc-ion batteries

Organic-inorganic hybridization has been explored to improve the electrochemical performance of electrodes for aqueous zinc-ion batteries. In this work, 4,4′-diamino-2,2′-bipyridine (DB) and 2,6-diaminoanthraquinone (DAAQ) intercalated vanadium pentoxide (HVO-DB and HVO-DAAQ) are prepared by pre-intercalation techniques. The incorporation of DAAQ and DB play a pivotal role in not merely enhancing the interlayer spacing of VOx slabs substantially, which consequently elevates the efficiency of ion diffusion processes, but also in reinforcing the overall structural stability through promoting the establishment of a robust hydrogen bond network. Moreover, the abundant CO redox-active sites present in DAAQ actively coordinate with Zn2+ during the insertion process, leading to a notable enhancement in specific capacity. HVO-DAAQ demonstrates an exceptional specific capacity of 395 mA h g−1 when charged at 0.1 A g−1, coupled with remarkable cycling stability, retaining 87.8 % of its capacity even after enduring 2000 cycles at a high rate of 5 A g−1, and superior rate performance. Ex-situ characterization reveals the exceptional reversibility of Zn2+ insertion, alongside the remarkable capacity of hydrogen bond networks to undergo disruption and subsequent reconstruction, showcasing a dynamic and resilient structural adaptability. Furthermore, this work provides insights into the synergistic energy storage mechanism in the organic-inorganic hybrids cathode for aqueous zinc-ion batteries.