Search Results (249)

The excessive use of herbicides in agricultural fields has emerged as a critical environmental concern. This study innovatively synthesized a ZIF-8@TPPa composite through a solvothermal method for the efficient removal of herbicides from aqueous environment. The material exhibited remarkable adsorption capacities for butachlor (232.56 mg/g), anilofos (188.68 mg/g), and pendimethalin (285.71 mg/g), along with excellent acid–base stability (pH 3–9), strong anti-ion interference capability, and good reusability (adsorption efficiency >80% after five cycles). The adsorption processes were well-described by the two isotherm models and the pseudo-second-order model, indicating that the dominant mechanism is a synergistic effect between monolayer chemical adsorption and multilayer physical adsorption, primarily driven by π-π stacking, hydrogen bonding, and coordination. The material maintained outstanding adsorption efficiency (>85%) in real water samples (tap water, seawater, and river water). This study not only provides a sustainable and effective strategy for herbicide remediation from aqueous environment but also expands the practical applications of MOF@COF in aqueous environment. Full article

Minimally invasive thread lifting has emerged as an effective strategy for soft tissue repositioning and facial rejuvenation; however, currently used absorbable threads generally lack intrinsic antimicrobial functionality, which may increase the risk of postoperative infection. Here, we report a biodegradable antibacterial lifting thread based on a nanocellulose/MOF composite system. The thread was fabricated via a green wet-spinning strategy using carboxymethylated cellulose nanofibrils (CCNF, prepared with cellulose derived from Astragalus residue) and sodium alginate (SA) as the structural matrix, while tetracycline hydrochloride-loaded ZIF-8 nanoparticles were incorporated to provide sustained antibacterial activity. The resulting antibacterial CCNF/SA thread (AB-CCNF/SA) exhibited a uniform morphology and a tensile strength of 80 MPa. The porous ZIF-8 carriers enabled efficient drug loading and controlled release, providing effective antibacterial activity against Staphylococcus aureus and Escherichia coli. Meanwhile, the composite threads showed favorable biodegradability, with approximately 45% degradation within 56 days, together with excellent cytocompatibility as demonstrated by fibroblast viability above 90%. In vivo studies further revealed inflammatory responses comparable to those of commercial collagen threads, confirming the good biocompatibility of the system. Overall, this work establishes a strategy for integrating nanocellulose structural materials with MOF-enabled antibacterial drug delivery, providing a multifunctional platform that combines mechanical support, biodegradability, and sustained antibacterial activity for minimally invasive soft tissue lifting and related biomedical implant applications. Full article

Meltable metal–organic frameworks (MOF) are essential for the formation of MOF glasses, which have emerged as a new family of functional materials offering promising potential for applications in gas separation, luminescence, energy storage, and beyond. Herein, the synthesis of iron-based zeolitic imidazolate framework (ZIF) crystals, specifically Fe₃(Im)₆(HIm)₂, where Im is imidazolate, is reported. Upon the substitution of some Im linkers with a secondary ligand, 5,6-dimethylbenzimidazole (dmbIm), it was found that such substitution induces the formation of new phases: one phase exhibits meltability and subsequent glass formation, while another phase [Fe₃(Im)_1.56(dmbIm)_4.44(HIm)₂] is non-meltable. Through structural characterizations, the configuration of the tetrahedral [Fe-linkers] units was revealed to be crucial in determining the meltability of Fe-ZIF. The incorporation of a large secondary ligand hinders the occurrence of melting. This work provides an insight into how ligands affect the accessibility of the liquid state of MOFs, showing a practical strategy for designing meltable MOFs. Full article

Trichloroethylene (TCE) is a pervasive groundwater contaminant, yet the practical application of nanoscale zero-valent iron (nZVI) is often limited by particle aggregation, rapid surface oxidation, and inefficient utilization of reactive electrons. Here, we developed a support–sulfidation coupled design to improve TCE dechlorination by integrating ZIF-8-enabled contaminant enrichment and dispersion with sulfidation-enabled surface-state regulation. A ZIF-8-supported sulfidated nZVI composite (ZIF-8@S-nZVI) was synthesized and systematically compared with nZVI, S-nZVI, and ZIF-8@nZVI. Among the tested materials, ZIF-8@S-nZVI exhibited the fastest TCE removal, the highest ethylene formation, and the highest chloride release, indicating the most effective dechlorination performance rather than merely adsorption-driven apparent removal. The optimal Fe:ZIF-8 mass ratio was 6:1. The composite also maintained high dechlorination capability over 20–40 °C, pH 6–9, and initial TCE concentrations of 10–40 mg/L, although 20 °C, near-neutral pH, and lower pollutant loading were kinetically more favorable. Multiscale characterization by FT-IR, N₂ adsorption–desorption and BET, XRD, EDS, SEM, and XPS indicated that ZIF-8 mitigated particle aggregation and retained partial pore accessibility, whereas sulfidation was associated with a more persistent Fe(II)-rich surface state after reaction. Together, these coupled effects promoted local TCE enrichment and sustained interfacial transformation. This study provides mechanistic insight and practical guidance for the rational design of MOF-supported sulfidated iron materials for chlorinated-solvent-contaminated groundwater remediation. Full article

Formic acid (FA) has emerged as a promising liquid hydrogen storage material, yet efficient photothermal dehydrogenation catalysts with high activity and H₂ selectivity remain challenging. Herein, a polymetallic synergistic PdCu/M-ZNC (where M represents the co-doped In, Sn and Mo species) is fabricated by molten-salt-assisted pyrolysis of ZIF-8 precursors followed by metal incorporation. The unique molten salt environment effectively preserves the porous architecture of ZIF-8, enabling the secure anchoring of PdCu alloy nanoparticles onto the carbonaceous matrix enriched with M-N_x coordination sites. Under light irradiation, the PdCu alloy sites kinetically accelerated the overall adsorption and activation of FA molecules. Based on empirical observations and corroborated by the established literature, this alloying effect was inferred to facilitate the C-H bond cleavage and HCOO* desorption processes. Concurrently, the M-N_x sites act as efficient electron transfer channels, facilitating the rapid coupling of photogenerated electrons with protons (H⁺) to evolve H₂. Consequently, the optimal catalyst exhibits an enhancement in gaseous product yield (404.46 mmol/g/h) and H₂ selectivity (67.49%) at 75 °C. This work offers a catalyst design that aligns with several principles of green chemistry: it maximizes the atom utilization of precious Pd, incorporates synergistic non-precious metals within MOF-derived frameworks to enhance stability, and leverages solar energy to drive hydrogen production under mild conditions, presenting a more sustainable pathway for hydrogen release from liquid carriers. Full article

Manganese-based cathodes offer high capacity, low cost, and safety for aqueous zinc-ion batteries (AZIBs), yet suffer from Mn dissolution, Jahn–Teller distortion, and sluggish Zn²⁺ kinetics. Herein, a Zn/Co co-doped MnO nanoporous carbon composite (denoted as ZnCo-MnO@NPC) derived from a bimetallic ZnCoMn metal–organic framework (ZnCoMn-MOF-74) is successfully synthesized and proposed as a high-performance cathode to address these challenges. The introduction of Zn²⁺ increases the initial specific capacity of MnO, while Co doping effectively suppresses the Jahn–Teller distortion and improves the integrity of the structure. Furthermore, the nanoporous carbon matrix facilitates electrolyte infiltration and accelerates ionic transport. To further suppress dendrite growth and enhance cycling stability, a zeolitic imidazolate framework (ZIF-8) protective layer is engineered on the zinc anode (denoted as ZIF-8@Zn), effectively mitigating dendrite formation. The ZnCo-MnO@NPC//ZIF-8@Zn full cell demonstrates superior electrochemical performance, delivering 281.3 mAh g⁻¹ at 0.1 A g⁻¹ and retaining 98.7% of this value after 3500 long-term cycles at 2.0 A g⁻¹, a remarkable finding that underscores its potential for high-performance energy storage. Collectively, this work highlights that transition metal ion doping represents an effective way to design efficient high-performance MOF-derived cathodes of AZIBs. Full article

Dopamine is a key neurotransmitter and neuromodulator that regulates many critical brain functions. Accurate monitoring of its level is essential for neuroscience as well as the diagnosis and treatment of many brain diseases. In this work, we developed a new electrochemical sensor, comprising phosphorus-doped graphitic carbon nitride (P-g-C₃N₄) and zeolitic imidazolate framework 67 (ZIF-67), for dopamine detection. In this composite electrode material, ZIF-67 provides numerous adsorption and sensing sites, while P-g-C₃N₄ enhances overall electrical conductivity and stability. Cyclic voltammetry tests reveal the redox behavior of dopamine at the surface of the composite electrode across various pH values and scan rates. Using differential pulse voltammetry, the sensitivity and selectivity of this dopamine sensor were assessed, identifying a limit of detection of 0.39 nM. Further successful quantification of dopamine in urine samples suggests the potential practical use of this new composite electrochemical sensor for detecting dopamine and/or other neurotransmitters. Full article

Biomineralization has recently emerged as a highly effective strategy for enzyme immobilization. Zeolitic imidazolate frameworks (ZIFs), a subclass of metal–organic frameworks (MOFs), are particularly attractive carriers due to their structural tunability and chemical stability. While ZIF-8 has been extensively studied, its denser and thermodynamically more stable analog ZIF-zni has received far less attention. In this work, we report the biomineralization of glucose oxidase (GOx) from Aspergillus niger within the ZIF-zni framework and systematically investigate the influence of zinc and imidazole (Im) concentration on immobilization performance. The optimized biocomposite, obtained at 10 mM Zn²⁺ and a Zn:Im ratio of 1:10, exhibited a specific activity of 2051 IU g⁻¹, which is more than twice the activity obtained for GOx@ZIF-8 in our previous study (874 IU g⁻¹). Furthermore, the GOx@ZIF-zni biocomposite demonstrated remarkable resistance to sodium dodecyl sulfate (SDS) and retained up to 50% of its activity after incubation at 65 °C for one hour. These results demonstrate that ZIF-zni is a highly promising carrier for enzyme immobilization and suggest that framework topology and synthesis conditions play a crucial role in determining the catalytic performance and stability of enzyme@MOF biocomposites. Full article

In this study, Ag-functionalized porous ZnO nanocomposites were successfully synthesized via pyrolysis of Ag-loaded ZIF-8 precursors. The structural and surface properties of the materials were systematically characterized using XRD, XPS, FESEM, and HRTEM analyses. A gas sensor fabricated from the optimized 3.0 wt% Ag–ZnO sample exhibited a significantly enhanced response (Ra/Rg = 103) toward 100 ppm acetone at an operating temperature of 275 °C, which is approximately 2.51 times greater than that of pristine ZnO. The sensor also demonstrated rapid response/recovery times (6 s/7 s), excellent linearity over a wide concentration range (500 ppb–200 ppm), good selectivity against common interfering VOCs, and stable performance, with over 95% response retention after 30 days. The improved sensing performance is attributed to the hierarchical porous structure derived from ZIF-8 and the increased oxygen vacancy concentration and chemisorbed oxygen species induced by Ag loading, which collectively increase surface reaction activity. This work provides an effective strategy for constructing noble metal-modified porous ZnO materials for sensitive and reliable acetone detection. Full article

Benefiting from their outstanding porosity, considerable specific surface area, and natural flexibility, cellulose nanofibers (CNFs)/MOF materials have emerged as competitive candidates for advanced flexible energy storage devices. However, conventional CNFs/MOFs aerogels or films often suffer from poor recoverability under compression, bending, and folding, accompanied by severe plastic deformation that compromises the cycling and structural stability of devices. To address this issue, we report a rationally designed flexible PU/CNFs/ZIF-8/PANI composite foam with an interconnected micro-mesoporous structure. Using polyurethane foam as a soft substrate and CNFs/ZIF-8 as building blocks, the composite was fabricated through a combined strategy of impregnation, in situ ZIF-8 growth, hot-pressing, and in situ aniline polymerization with simultaneous etching of the ZIF-8. The incorporation of carboxylated CNFs enhances the hydrophilicity of the PU skeleton. This, in combination with the hot-pressed framework, establishes an interconnected 3D network, thereby effectively preventing the agglomeration of active materials. Meanwhile, the hierarchical pores derived from the sacrificial ZIF-8 template provide abundant electroactive sites, accelerate ion transport, and facilitate high PANI loading. By virtue of this synergistic architectural effect, the resultant electrode achieves a high specific capacitance of 449 F/g at 0.2 A/g, with 97% capacitance retention after 2000 cycles at 5 A/g. Furthermore, the composite foam demonstrates excellent mechanical flexibility, with a tensile strength of 0.87 MPa and an elongation at break of 230%. This work offers a feasible approach for developing high-performance flexible supercapacitors and provides novel perspectives for the rational design of portable energy storage devices. Full article

Herein, an electrochemical sensor is reported for the first time based on an ordered macro–microporous composite derived from metal–organic frameworks (MOFs) for the highly sensitive detection of auramine O (AO), a Group 2B carcinogen. The hierarchical pore architecture, integrating an ordered macroporous network with a microporous ZIF-8 framework, enables the uniform dispersion of a high density of catalytically active sites. The interconnected macroporous channels facilitate efficient mass transport and rapid removal of reaction byproducts, effectively preventing pore blockage and ensuring stable sensing performance during repeated measurements. Owing to these structural advantages, the proposed sensor exhibits outstanding analytical performance toward AO detection, with a sensitivity of 0.4843 μA μM⁻¹, a detection limit of 0.168 μM (S/N = 3), and a wide linear range from 0.5 to 50 μM. Moreover, the sensor demonstrates excellent selectivity and reproducibility, maintaining reliable responses even in the presence of 100-fold excess common food constituents such as tartrazine and glucose. Real sample analysis further confirms its high accuracy and operational stability. Overall, the electrochemical sensor based on silver nanoparticle-decorated ordered macro–microporous ZIF-8 synthesized via in situ reduction shows great potential as a portable and on-site tool for rapid AO detection in food. More broadly, ordered macro–microporous MOF-derived materials represent a promising platform for advanced electrochemical sensor applications. Full article

Transition metal oxides (TMOs) have been recognized as highly prospective anode materials for lithium-ion batteries (LIBs) due to their low cost, high capacity, and distinctive lithiation mechanisms. Nevertheless, their practical adoption is constrained by significant volume changes during lithiation/delithiation, inferior electrical conductivity, severe particle agglomeration, unsatisfactory cycling stability, and limited rate performance. In an effort to mitigate these flaws, we developed a tactic employing a zeolitic imidazolate framework (ZIF) as the self-sacrificing template and tuning the Co/Fe/Ni ratio with a ZIF framework to prepare an innovative trimetallic metal–organic framework (MOF)-derived CoNiO₂/NiCo₂O₄/NiFe₂O₄ compound (CFNO422) with nano/micro hierarchical architecture. The nano/micro hierarchical structure effectively accommodates volume changes, alleviates structural stress, and offers copious active sites for lithium storage. More importantly, the synergistic interaction among multiple component oxides promotes richer redox reactions and enhances electronic conductivity. Benefiting from the structural compatibility and composition, CFNO422 delivers an outstanding reversible capacity (1301.3 mAh g⁻¹ up to 120 cycles at 0.2 A g⁻¹), enhanced rate capability (614.3 mAh g⁻¹ even at 2.0 A g⁻¹), and exceptional cycling stability (527.4 mAh g⁻¹ over 600 cycles at 1.0 A g⁻¹). This research proposes a versatile synthesis for MOF-derived polymetallic oxides as anode materials, opening a new avenue for advanced energy storage. Full article

The accurate monitoring of nitrite levels is critically important for safeguarding public health and ensuring food safety, as excessive intake presents severe risks. In this study, we developed a highly sensitive electrochemical sensor for nitrite detection utilizing a cobalt-embedded porous carbon material derived from zeolitic imidazolate frameworks (ZIFs) of ZIF-9. The precursor was subjected to pyrolysis at various temperatures, revealing that the sample carbonized at 800 °C (ZIF-9-800) exhibited superior electrocatalytic performance. This enhancement is attributed to its optimized graphitization degree, high specific surface area, and the well-dispersed active sites resulting from the in situ generated cobalt nanoparticles. The ZIF-9-800-based sensor demonstrated outstanding electrochemical performance, achieving a broad linear detection range of 0.2–7000 μM, high sensitivity (848.6 μA mM⁻¹ cm⁻²), and an impressively low detection limit of 50 nM. Furthermore, the sensor exhibited excellent selectivity in the presence of common interfering ions and remarkable long-term stability, maintaining more than 80% of its initial response after extended storage. This work underscores the effectiveness of MOF-derived carbon-based catalysts, tailored through calcination temperature optimization, for constructing advanced electrochemical sensing platforms. Full article

Background: Food waste contains abundant (+)-catechin, but its efficient recovery remains challenging. This study aimed to prepare ionic liquid (IL)-modified sorbents and establish an efficient method for (+)-catechin recovery from chocolate waste via solid-phase extraction (SPE). Methods: Three series of IL-modified sorbents (Sil-IL, ZIF67-IL, Sil@ZIF67-IL) were synthesized. Their adsorption performance was evaluated under different conditions; adsorption isotherm and kinetic data were fitted to Langmuir/Freundlich and pseudo-first/second-order models, respectively. Sorbent stability and (+)-catechin recovery from chocolate waste extracts were tested. Results: Sil@ZIF67-Hmim showed the highest adsorption capacity (154.4 mg/g) at 25 °C within 120 min. Adsorption followed the Langmuir model (R² = 0.99), indicating chemisorption. Sil@ZIF67-Hmim was subjected to repeated solid-phase extraction (SPE) for five consecutive days; the recovery rate ranged from 98.1% to 99.2%, and the relative standard deviation (RSD) was 3.2–4.4%. Conclusions: Sil@ZIF67-Hmim is a high-efficiency sorbent for (+)-catechin recovery from chocolate waste, providing a novel approach for food waste valorization and highlighting the application potential of IL-modified MOF-silica composites. Full article

Gas sensors based on metal oxide semiconductors (MOS) have attracted significant attention in monitoring of methane emission and leakage monitoring due to their high sensitivity, fast response time, simple structure and low cost. However, the high power consumption caused by long-term high-temperature operation of MOS sensors restricts their application in mobile and portable devices. In this study, MOF-derived Co₃O₄ dodecahedrons for low-concentration methane detection at room temperature was prepared using Zeolitic Imidazolate Framework-67 (ZIF-67) as a template and with various calcination temperatures. Among them, the Co₃O₄-350 calcined at 350 °C exhibited the optimal CH₄ sensing performance at room temperature, with a response of R_g/R_a = 1.53 to 2000 ppm CH₄. This enhanced gas sensing performance is attributed to the highest Co³⁺ proportions and the largest specific surface area in Co₃O₄-350 nanomaterials, which provided more active sites for gas adsorption and reaction. To address the challenge of slow response speed and irrecoverability during CH₄ detection at room temperature, the Co₃O₄ nanomaterials were printed onto a micro-heater plate (MHP) to form a MEMS gas sensor. By introducing a pulse heating mode to the MEMS sensor, the response and recovery time were significantly reduced to 26 s and 21 s, respectively. This enhancement improves both the efficiency and reliability of the MEMS gas sensor for early-stage detection of CH₄ leaks in various industrial applications. Full article