Metal-organic Framework Materials Research Articles

Self-enhancement of bioenergy recovery from anaerobically digesting WAS with novel iron-based metal-organic framework assistance: Insights into electron transfer and metabolic pathways

Inadequate methane production and insufficient hydrolysis-acidification activity impede the practical application of anaerobic digestion (AD) of waste activated sludge (WAS). Recently, metal-organic framework (MOF) materials attains promising capability of controlling proton/electron transfer in AD processes. This study used a typical iron-based MOF and MIL-88A(Fe) to improve the methane production via digesting WAS. These materials were prepared via a one-step hydrothermal method. The findings indicated that the addition of 150 mg MIL-88A(Fe)/g WAS VS resulted in a 57.23% increase in accumulated methane production and a 43.84% increase in daily maximum methane production. The methane production rate (Rmax) also increased from 22.25 to 29.14 mL/g VS/d. The enhanced electron transfer capacity, improved hydrolysis of WAS, boosted acetate generation, and mitigated accumulation of volatile fatty acids (VFAs) collectively contributed to the better methane yield in the MIL-88A(Fe)-added system. The significant enrichment of Methanobacterium and Methanosaeta along with the up-regulation of key methanogenesis enzyme-encoding genes jointly suggested that the CO2 reduction and methanogenesis were strengthened. Moreover, MIL-88A(Fe) stimulated the production of c-type cytochrome and e-pili, facilitating direct interspecies electron transfer (DIET) between norank-f-SC-I-84 and Methanobacterium. This study provided new solutions for improving methane production and offered insights into the mechanism of enhanced methanogenesis of AD in the presence of MIL-88A(Fe).

Microfluidic Synthesis of Defective and Hierarchical Pore Zr Metal–Organic Framework Materials and CO2 Adsorption Performance Study

Microfluidic Synthesis of Defective and Hierarchical Pore Zr Metal–Organic Framework Materials and CO₂ Adsorption Performance Study

Defect strategies in Mn-doped metal–organic frameworks to enhance adsorption-based NOx gas sensing performance

Post-synthetic metalation (PSM) represents a powerful toolkit for modifying the chemical composition of pre-formed metal-organic frameworks (MOFs). However, accessing defective MOFs with exchanged metal nodes via this approach remains challenging. Herein, we report a transmetalation strategy to induce desired metal exchange frustrated flexibility defects in a prototypical MOF platform. Specifically, the pristine Zn-based MOF undergoes selective Zn-to-Mn exchange through a carefully controlled solvothermal transmetalation process. This protocol generates a series of Mn-doped MOFs with increasing Mn integration and the concomitant formation of defect sites within the framework. Detailed structural characterization confirms the successful Mn doping and illuminates the generation of vacancies and distortions around the exchanged Mn nodes. The transmetallated Mn-doped MOF materials exhibit altered chemical environments, as probed by spectroscopic techniques, and display promising sensing activity for NOx through the MOF matrix membrane. The proposed application of the MOF samples as an adsorbent-based chemical sensor includes sensing mechanisms for NO2 gas.

Mechanism of Enhanced Fluoride Adsorption Using Amino-Functionalized Aluminum-Based Metal–Organic Frameworks

Due to the increasing fluoride concentrations in water bodies, significant environmental concerns have arisen. This study focuses on aluminum-based materials with a high affinity for fluorine, specifically enhancing metal–organic frameworks (MOFs) with amino groups to improve their adsorption and defluorination performance. We systematically investigate the factors influencing and mechanisms governing the adsorption and defluorination behavior of amino-functionalized aluminum-based MOF materials in aqueous environments. An SEM, XRD, and FT-IR characterization confirms the successful preparation of NH2-MIL-101 (Al). In a 10 mg/L fluoride ion solution at pH 7.0, fluoride ion removal efficiency increases with the dosage of NH2-MIL-101 (Al), although the marginal improvement decreases beyond 0.015 g/L. Under identical conditions, the fluoride adsorption capacity of NH2-MIL-101 (Al) is seven times greater than that of NH2-MIL-101 (Fe). NH2-MIL-101 (Al) demonstrates effective fluoride ion adsorption across a broad pH range, with superior fluoride uptake in acidic conditions. At a fluoride ion concentration of 7 mg/L, with 0.015 g of NH2-MIL-101 (Al) at pH 3.0, adsorption equilibrium is achieved within 60 min, with a capacity of 31.2 mg/g. An analysis using adsorption isotherm models reveals that the fluoride ion adsorption on NH2-MIL-101 (Al) follows a monolayer adsorption model, while kinetic studies indicate that the predominant adsorption mechanism is chemical adsorption. This research provides a scientific basis for the advanced treatment of fluoride-containing wastewater, offering significant theoretical and practical contributions.

In situ generation of cuprous oxide in metal-organic framework for significantly enhanced room-temperature ammonia sensing: Synergy enabling excellent sensitivity and selectivity

Development of effective strategies to improve the response sensitivity of metal-organic frameworks (MOFs) to target gases is imperative to further enhancing their application potential in gas sensing. In this work, series of CuHHTP/Cu2O (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) composites are successfully constructed by in-situ electrochemical reduction treatment of CuHHTP, and the changing trend of first increasing and then decreasing with increase of CuHHTP electrochemical reduction degree for their sensitivity to NH3 detection is revealed. When the average size of Cu2O nanoparticles generated in CuHHTP is 3.6 nm, the corresponding CuHHTP/Cu2O-A composite exhibits the best NH3 sensing performance compared to pristine CuHHTP, including significantly enhanced response sensitivity, ultralow experimental detection limit of 10 ppb, superior selectivity, good reproducibility, and excellent response stability even after placed for 90 days. More impressively, thanks to integration and synergy of the uniformly-dispersed small-sized Cu2O nanoparticles with significantly enhanced adsorption activity and capacity for NH3, the released large amount of uncoordinated hydroxyl groups that can interact with NH3, as well as the active sites of the CuHHTP substrate itself, the 10 ppb experimental detection limit for the CuHHTP/Cu2O-A-based sensors is not only the lowest one reported in the past 10 years for NH3 sensors based on copper-containing MOF and oxide materials, but also superior to that of 0.1–1 ppm for the existing commercial NH3 sensors. This work opens the avenue for design and development of novel MOF-based sensing materials.

Separation of the cis- and trans-isomers 1,4-cyclohexanedicarboxylic acid by a dynamic MOF

Achieving an efficient method to separate cis–trans isomers of trans-1,4-cyclohexanedicarboxylic acid remains a formidable challenge within the chemical industry. Here, we have synthesized a Co(II)-based dynamic metal–organic framework material involving the coordination of 1,4-cyclohexanedicarboxylic acid. Single-crystal X-ray diffraction and high-performance liquid chromatography (HPLC) analysis confirmed that only pure trans-1,4-cyclohexanedicarboxylic acid was present in all synthesized crystals, a characteristic that can be utilized for the separation of the cis- and trans-isomers of 1,4-cyclohexanedicarboxylic acid. Moreover, the MOF crystals displayed reversible structural changes and were capable of releasing the pure trans-isomer through ion exchange with a salt solution, underscoring their potential for applications in molecular separation.

Molecular Simulation of Cyclohexane in Nanoporous Materials: Adsorption of Conformers and Coadsorption with Water and Carbon Dioxide.

Molecular simulation is used to investigate the adsorption of an organic molecule and its different conformers into various nanoporous adsorbents. In more detail, we perform grand canonical Monte Carlo simulations to determine the adsorption isotherms for cyclohexane with its three conformers (chair, boat, and twisted boat) at three different temperatures into a molecular model of active carbons and two metal-organic frameworks (MOFs) (Cu-BTC and Al-Fum). By considering the adsorption of each conformer separately, we show that the adsorption isotherms are weakly dependent on the molecular conformation. When considering the concomitant adsorption of the three conformers under realistic conditions (to verify the population of each conformer in bulk mixtures), we show that the chair conformer is predominantly adsorbed in each material. However, such favorable adsorption mostly reflects the fact that this conformer has the largest population in the bulk mixture under the same thermodynamic conditions. On the contrary, with an increase in the cyclohexane gas pressure, the adsorption of boat and twisted boat conformers increases, while that of the chair conformer decreases as packing (entropy) effects become predominant during confinement. The adsorption of cyclohexane in the active carbon and MOF materials is also considered in the presence of water and CO2 atmospheres. In the case of the Al-fumarate material, the material is found to be strongly organophilic so that water and CO2 adsorption are negligible, and cyclohexane adsorption is not affected by competitive adsorption under any considered thermodynamic condition. On the contrary, for the active carbon and Cu-BTC material, competitive adsorption between cyclohexane and water or CO2 is observed even if cyclohexane adsorption remains preferred. While the different molecules coexist in the adsorbed phase at low pressures, increasing the cyclohexane pressure beyond 103 Pa promotes cyclohexane adsorption concomitantly with water and/or CO2 desorption.

Bioinspired recognition in metal-organic frameworks enabling precise sieving separation of fluorinated propylene and propane mixtures

The separation of fluorinated propane/propylene mixtures remains a major challenge in the electronics industry. Inspired by biological ion channels with negatively charged inner walls that allow selective transport of cations, we presented a series of formic acid-based metal-organic frameworks (MFA) featuring biomimetic multi-hydrogen confined cavities. These MFA materials, especially the cobalt formate (CoFA), exhibit specific recognition of hexafluoropropylene (C3F6) while facilitating size exclusion of perfluoropropane (C3F8). The dual-functional adsorbent offers multiple binding sites to realize intelligent selective recognition of C3F6, as supported by theoretical calculations and in situ spectroscopic experiments. Mixed-gas breakthrough experiments validate the capability of CoFA to produce high-purity (>5 N) C3F8 in a single step. Importantly, the stability and cost-effective scalable synthesis of CoFA underscore its extraordinary potential for industrial C3F6/C3F8 separations. This bioinspired molecular recognition approach opens new avenues for the efficient purification of fluorinated electronic specialty gases.

In Situ Synthesis of Copper-Based Metal-Organic Frameworks with Ligand Defects for Electrochemical Reduction of CO2 into C2 Products.

Electrochemical reduction of CO2 into high-value-added products is a potential approach to solving environmental problems but is limited by poor product selectivity and low efficiency. Metal-organic framework (MOF) materials have been considered one of the most promising catalysts, but their application is limited by complicated preparation processes, especially during the synthesis of organic ligands. In this work, a new three-dimensional Cu-MOF (JXUST-301) with high porosity was constructed based on the naphthalene diimide (NDI) ligand. Furthermore, JXUST-301 with ligand defects (JXUST-301D) originating from the missing NDI unit was synthesized via an in situ reaction. The presence of ligand defects endows JXUST-301D with a better CO2RR performance with a FEC2 of 56.7% and a jC2 of -162.4 mA cm-2. Mechanistic studies revealed that the hierarchical pore structure and amino sites are created from the absence of the NDI unit, which promotes the exposure of catalytically active sites and CO2 enrichment. Furthermore, the electronic structure of the Cu sites is modulated to upshift the d-band center, facilitating chemical adsorption and activation of key reaction intermediates. This work provides new insight into the in situ preparation of efficient Cu-MOF catalysts by introducing defects for the CO2RR.

Ammonia Storage in Metal-Organic Framework Materials: Recent Developments in Design and Characterization.

Since the advent of the Haber-Bosch process in 1910, the global demand for ammonia (NH3) has surged, driven by its applications in agriculture, pharmaceuticals, and energy. Current methods of NH3 storage, including high-pressure storage and transportation, present significant challenges due to their corrosive and toxic nature. Consequently, research has turned towards metal-organic framework (MOF) materials as potential candidates for NH3 storage due to their potential high adsorption capacities and structural tunability. MOFs are coordination networks composed of metal nodes and organic linkers, offering unprecedented porosity and surface area, and allowing incorporation of various functional groups and metal sites that can enhance NH3 adsorption. However, the stability of MOFs in the presence of NH3 is a significant concern since many degrade upon exposure to NH3, primarily due to ligand displacement and framework collapse. To address this, recent studies have focused on the synthesis and postsynthetic modification of MOFs to enhance both NH3 uptake and stability. In this Account, we summarize recent developments in the design and characterization of MOFs for NH3 storage. The choice of metal centers in MOFs is crucial for stability and performance. High-valence metals such as AlIII and TiIV form strong metal-linker bonds, enhancing the stability of the framework to NH3. The MFM-300 series of materials composed of high-valence 3+ and 4+ metal ions and carboxylic linkers demonstrates high stability and high NH3 uptake capacities. Ligand functionalization is another effective strategy for improving the NH3 adsorption. Polar functional groups such as -NH2, -OH, and -COOH enhance the interaction between the framework and NH3, particularly at low partial pressures, while postsynthetic modification allows fine-tuning of these functionalities to optimize the framework for higher adsorption capacities and stability. For example, MFM-303(Al), incorporating free carboxylic acid groups, exhibits a high NH3 packing density comparable to that of solid NH3. Creating defect sites by removing linkers or adding metal ions increases the number of active sites available for NH3 adsorption and shows promise for enhancing uptake. UiO-66, a stable MOF framework, can be modified to include defect sites, significantly enhancing the level of NH3 uptake. The full characterization of MOFs and especially their interactions with NH3 are vital for understanding and improving their performance. Techniques such as neutron powder diffraction (NPD), inelastic neutron scattering (INS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), electron paramagnetic resonance (EPR) spectroscopy, and solid-state nuclear magnetic resonance (ssNMR) spectroscopy can elucidate host-guest interactions and binding dynamics between NH3 and the framework structure and afford crucial information for the future design and rational development of new sorbents. This Account highlights our current strategies for the synthesis and characterization of MOFs for NH3 capture, providing an overview of this rapidly evolving field.

Fine-Scale Aerosol-Jet Printing of Luminescent Metal-Organic Framework Nanosheets.

Fabrication of metal-organic framework (MOF) thin films is an ongoing challenge to achieve effective device integration. Inkjet printing has been employed to print various luminescent metal-organic framework (MOF) films. Luminescent metal-organic nanosheets (LMONs), nanometer-thin particles of MOF materials with comparatively large micrometer lateral dimensions, provide an ideal morphology that offers enhancements over analogous MOFs in luminescent properties such as intensity and photoluminescent quantum yield. The morphology is also better suited to the formation of thin films. This work harnesses the preferential features of LMONs to access the advanced technique of aerosol-jet printing (AJP) to print luminescent films with precise geometries and patterns across the micrometer and centimeter length scales. AJP of LMONs exhibiting red (R), green (G), and blue (B) emission were studied systematically to reveal the increase of luminescence upon additive layering printing until a threshold was reached limited by self-quenching. By combining different LMON emitters, emission chromaticity and intensity were shown to be tunable, including the combination of RGB emitters to fabricate white-light-emitting films. A white-light LMON film was printed onto a UV light emitting diode (LED), producing a working white-light-emitting diode. Printing with multiple distinct photoluminescent inks produced intricate multicolor patterns that dynamically responded to excitation wavelength, acting either as micrometer-scale LED-type cells or larger visual tags. Collectively, the work offers an advancement for MOF thin films by printing MON materials using AJP, offering a precise method for manufacturing a wide range of critical functional devices, from luminescent sensors to optoelectronics, and more broadly even the opportunity for printed circuitry with conductive MONs.

Cu-trimesate and mesoporous silica composite as adsorbent showing enhanced CO2/CH4 and CO2/N2 selectivity for biogas and flue gas separation

Due to their diverse structure, high porosity, and tunable functionality, Metal-Organic Frameworks (MOFs) hold great potential as materials for diverse applications, including gas separation. Material science researchers are focusing on creating flexible materials that have special properties. Most of the latest research mainly concentrates on fabricating composite materials of MOFs and other functional materials. These MOF-based composites can mitigate the limitations of pure MOFs and may even perform better than the individual components. Here, we present a systematic study on the effect of solvent in synthesising a composite (Cu-BTC@SBA-15) of Cu-trimesate MOF (aka CuBTC) and ordered mesoporous silica SBA-15, showing considerable improvement in selectivity for CO2 adsorption from the flue gas and biogas. The pristine Cu-BTC, SBA-15 and the composites with different content of Cu-BTC were characterized by PXRD, BET, FT-IR, SEM, TEM and TGA techniques. The pure gas adsorption isotherms were measured for CO2, CH4, and N2 gases. Ideal Adsorbed Solution Theory (IAST) is used for the binary selectivity calculations for gas systems such as CO2/CH4 and CO2/N2 in the context of biogas and flue gas separation. The composite exhibited an increase in CO2/CH4 selectivity by 39 % compared to pure Cu-BTC and 85 % compared to pure SBA-15. For the CO2/N2 system, the composite showed 38 % higher selectivity than Cu-BTC. The work has significance in the design of effective MOF-based composites for CO2 separation. Our work might open up a new route to design multifunctional materials for worldwide applications through an adsorptive and or mixed matrix membrane route.

Efficient degradation of norfloxacin by synergistic activation of PMS with a three-dimensional electrocatalytic system based on Cu-MOF

In this work, Cu-based metal-organic framework material (Cu-MOF) was combined with an electric field to construct a three-dimensional electrocatalytic synergistic activation of peroxymonosulfate sulfate (PMS) system (3D/Cu-MOF/EC/PMS) for the degradation of norfloxacin (NOR). The results show that the synergistic degradation efficiency of the Cu-MOF material with the electric field is enhanced by nearly 64 % relative to the degradation efficiency of the two alone. The quenching experimental and EPR characterization indicates that ROS plays an important role in the degradation process, with O2– playing a dominant role. Finally, the degradation pathway of NOR was explored by DFT study and LC-MS tests, and the toxicity evaluation software (TEST) and CCK-8 cytotoxicity experimental studies demonstrated that the sewage after the degradation of NOR by this system would have little or no effect on human liver cells (L02). This study not only shows that the 3D/Cu-MOF/EC/PMS system can treat the water containing higher concentrations of NOR into a state that is not harmful to the human body but also provides a new idea for the improvement of catalysts that do not have obvious catalytic degradation effects.

Study of [Cu3(C6H3(COO)3)2(H2O)3]n (HKUST-1) Resistance to Gamma Radiation at Dose of 125 kGy to 200 kGy

Abstract Adsorption is one of the methods for processing gas and liquid radioactive waste to prevent the dispersion of substances into the environment. The metal-organic framework (MOF) material HKUST-1, known for its porous structure, exhibits impressive adsorption capacity and efficiency. These characteristics make it highly suitable as a radioactive waste adsorbent. This study aims to assess its resilience to gamma radiation by exposing it to doses ranging from 125 to 200 kGy, with a 25 kGy interval. The samples used in this research were produced using the solvothermal method at 100°C. Subsequently, the irradiated samples underwent evaluation using XRD, SEM, and isothermal adsorption with nitrogen gas. As the dose increased, the crystal grain size decreased, resulting in sharper crystal corners. Additionally, the crystallinity value rose from 15.49% to 17.70%. However, at a dose of 175 kGy, the crystalline corners became obtuse, and the degree of crystallinity decreased to 16.21%. Based on the isothermal adsorption results, the adsorbed gas volume increased from 212.186 cm3/g to 340.335 cm3/g, the surface area expanded from 520.379 m2/g to 917.048 m2/g, and the pore volume grew from 0.424 cm3/g to 0.615 cm3/g. In contrast, the pore radius decreased from 1.631 nm to 1.341 nm, except at 175 kGy, where it measured 1.399 nm. This result surpassed the sample irradiated at 150 kGy, which had a pore radius value of 1.352 nm.

Different FeS Concentrations for Encapsulating ZIF-67 Nanomaterials toward the Enhanced Oxidation Evolution Reaction.

Due to the slow kinetic nature of the oxygen evolution reaction (OER), the development of electrocatalysts with high efficiency, stability, and economy for oxygen production using metal-organic framework (MOF) materials is still a challenging research topic. In this work, we chose the different concentrations of FeS adsorption to encapsulate metal cobalt-based ZIF-67 MOF for preparing a series of electrocatalysts (ZIF1FeSx, x = 0.2, 0.5, 0.75, and 1), which were mainly explored for the electrocatalytic OER. Among them, ZIF1FeS0.5 has excellent electrocatalytic activity for OER, which can be driven by low overpotentials of 276 and 349 mV at 10 and 50 mA cm-2 current densities, and more than 92% of the initial overpotential can be maintained after 100 h of continuous OER at 10 mA cm-2 current density. This is mainly due to the electronic interactions between the cobalt-based MOF and the FeS, which shift the electronic state of the active metal center to a higher valence state for increasing the number of active sites and enhancing the efficiency of electron transfer to facilitate the OER course. This work may contribute to the design of effective catalysts for the OER during the electrolysis of alkaline solutions.

SnO2-x/CD-MOF S-Scheme heterostructure photocatalysts synergized by oxygen vacancies and highly porous for rhodamine B and tetracycline degradation: Process, and mechanism analysis

To enhance the performance of environmentally friendly cyclodextrin metal-organic framework (CD-MOF) materials for more effective removal of organic pollutants and wastewater treatment, also the composites underwent optimization, and the adsorption-enhanced photocatalytic mechanism was thoroughly investigated. This study presents the synthesis of novel SnO2-x/CD-MOF (SCM) photocatalysts were prepared by a simple solvothermal method, which were characterized by oxygen vacancies (OVs), high specific surface area and heterojunction. SCM exhibited outstanding photodegradation performance for rhodamine B (RhB) and tetracycline (TC) when exposed to visible light. Specifically, the RhB removal efficiency was an impressive 93.5 %, achieved with a degradation rate constant of 0.0484 min−1, while the removal efficiency of TC was 83.1 %, with a degradation rate constant of 0.0246 min−1. The photodegradation activity of SCM was predominantly influenced by ·O2-, h+, and ·OH. The mechanism of action involves three phases: adsorption, photocatalysis, and desorption-diffusion. The exceptional performance of SCM in terms of photocatalysis can be gave the credit to the synergistic effect of the high specific surface area of γ-CD-MOF and the oxygen vacancy-induced enhancement of SnO2-x catalytic activity. TC degradation intermediates and possible degradation pathways were analyzed and the toxicity of the intermediates was assessed. This study introduces a novel approach to designing CD-MOF-based photocatalysts.

In-situ preparation of lanthanide luminescent MOF hydrogel for aldehyde detection☆

Metal-organic frameworks (MOFs) usually exist in the state of powder or crystal. When they are exposed to hydrophilic solvents, their structure will change and become unstable. Therefore, it is a challenge to construct MOF materials with tunable mechanical properties. Herein, we report in-situ growth lanthanide metal-organic framework (LnMOF) in sodium alginate (SA) and polyvinyl alcohol (PVA) hydrogel matrix. The prepared composite hydrogel not only displays characteristic lanthanide narrow-band emission under ultraviolet light, but also demonstrates excellent mechanical properties. The addition of LnMOF significantly enhances the compressive strength of the hydrogel (from 0.75 to 7.32 MPa). Furthermore, the composite hydrogel shows highly selective recognition of glutaraldehyde and gaseous formaldehyde at room temperature. The detection limits (LOD) of SP-EuMOF for glutaraldehyde and formaldehyde are 0.27 and 0.22 ppm, respectively. Based on these results, the LnMOF composite hydrogel is deemed to have significant potential as a fluorescent sensor for both glutaraldehyde and formaldehyde detection.

Degradation of organic dyes by Peroxymonosulfate activated with Zn/Co-ZIF

In this study, we successfully synthesized a bimetallic metal-organic framework material Zn/Co-ZIF to start Peroxymonosulfate (PMS) for organic dye degradation in the water body. Material characterization was evaluated by advanced methods, such as XRD, FT-IR, SEM, EDX, and BET. The influence of different factors on methylene blue (MB) decomposition rate was investigated. The results show that Zn/Co-ZIF has a porous structure, a high specific surface area and decomposes 98.22% MB (20 mg/L) in 4 minutes under reaction conditions of 40 mg/L catalyst, 0.814mM PMS, pH = 7. The decomposition efficiency of dyes increases in the order CR (79.85%) <RhB (90.81 %) < DB71 (96.07%) < MO (97.63%) < MB (98.22%). The main ROS for the degradation MB in this study were SO4—-, O2—- and 1O2. This shows that Zn/Co-ZIF materials are potential heterogeneous catalysts to activate PMS to decompose organic pollutants in water.

Rapid screening of xanthine oxidase inhibitors from Ligusticum wallichii by using xanthine oxidase functionalized magnetic metal-organic framework.

In this study, xanthine oxidase was immobilized for the first time using a novel magnetic metal-organic framework material (Fe3O4-SiO2-NH2@MnO2@ZIF-8-NH2). A ligand fishing method was established to rapidly screen XOD inhibitors from Ligusticum wallichii based on the immobilized XOD. Characterization and properties of the immobilized enzyme revealed its excellent stability and reusability. A ligand was screened from Ligusticum wallichii and identified as ligustilide by ultra-high performance liquid chromatography tandem mass spectrometry. The IC50 value of ligustilide was determined to be 27.70 ± 0.13μM through in vitro inhibition testing. Furthermore, molecular docking verified that ligustilide could bind to amino acid residues at the active site of XOD. This study provides a rapid and effective method for thepreliminary screening of XOD inhibitors from complex natural products and has great potential for further discovery of anti-hyperuricemic compounds.

Modulation of metal centers of MOF in-situ grown on lignin-derived carbon to enhance adsorption capacity and electrochemical sensing performance for bisphenol A

Metal-organic framework materials have unique advantages in providing active sites and shortening electron/proton transfer distances. Here, an efficient electrochemical sensing material LPC-700@NiCo-MOF has been obtained by in-situ growth of bimetallic NiCo-MOF on lignin-derived porous quasi-carbon nanosheets (LPC-700). Due to the electronic synergistic effect of bimetallic centers of NiCo-MOF, it has better electrochemical sensing performance for bisphenol A (BPA) than the monometallic MOF. The density of states and adsorption energies of monometallic and bimetallic MOF on BPA have been investigated by DFT theory, which further demonstrated that the bimetallic NiCo-MOF has better electrochemical performance and adsorption effect on BPA. The high-performance portable sensor based on LPC-700@NiCo-MOF has been able to quickly, sensitively and accurately detect BPA in water samples and food packaging. This strategy of metal-modulated MOF grown in-situ on conducting carbon-based materials to enhance electrochemical activity provides a method for application in electrochemical fields.