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1.
Biochem Biophys Res Commun ; 702: 149649, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38341924

RESUMO

Acute pancreatitis (AP) is a severe inflammatory condition with a rising incidence and high mortality rates, especially in severe cases. Emodin (ED), known for its potent anti-inflammatory properties, holds promise in addressing AP. However, its clinical application is hindered by limitations such as low bioavailability and insufficient target specificity. Herein, we developed a novel drug delivery system using macrophage membrane-coated UiO-66-NH2 nanoparticles loaded with ED (MVs-UiO-ED). UiO-66-NH2 was successfully synthesized and characterized, revealing an octahedral structure with a suitable size distribution. The successful loading of ED onto UiO-66-NH2 was confirmed by ultraviolet and infrared spectroscopy. Subsequently, MVs-UiO-ED was prepared by coating macrophage membrane-derived vesicles onto UiO-ED, resulting in a biomimetic delivery system. In vitro release studies demonstrated that MVs-UiO-ED exhibited a sustained-release profile, indicating its potential for prolonged drug circulation. An AP mouse model was established to evaluate the therapeutic efficacy of MVs-UiO-ED. Compared with the model group, MVs-UiO-ED significantly reduced serum levels of α-amylase and lipase, two indicators of pancreatitis severity. Furthermore, histopathological examinations revealed that MVs-UiO-ED ameliorated pancreatic tissue damage. This study underscores the potential of MVs-UiO-ED as an effective therapeutic approach for AP.


Assuntos
Emodina , Estruturas Metalorgânicas , Nanopartículas , Compostos Organometálicos , Pancreatite , Ácidos Ftálicos , Camundongos , Animais , Pancreatite/tratamento farmacológico , Pancreatite/patologia , Emodina/uso terapêutico , Doença Aguda , Biomimética , Nanopartículas/química , Macrófagos/patologia
2.
Small ; : e2402819, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38837885

RESUMO

Janus-micromotors, as efficient self-propelled materials, have garnered considerable attention for their potential applications in non-agitated liquids. However, the design of micromotors is still challenging and with limited approaches, especially concerning speed and mobility in complex environments. Herein, a two-step spray-drying approach encompassing symmetrical assembly and asymmetrical assembly is introduced to fabricate the metal-organic framework (MOF) Janus-micromotors with hierarchical pores. Using a spray-dryer, a symmetrical assembly is first employed to prepare macro-meso-microporous UiO-66 with intrinsic micropores (<0.5 nm) alongside mesopores (≈24 nm) and macropores (≈400 nm). Subsequent asymmetrical assembly yielded the UiO-66-Janus loaded with the reducible nanoparticles, which underwent oxidation by KMnO4 to form MnO2 micromotors. The micromotors efficiently generated O2 for self-propulsion in H2O2, exhibiting ultrahigh speeds (1135 µm s-1, in a 5% H2O2 solution) and unique anti-gravity diffusion effects. In a specially designed simulated sand-water system, the micromotors traversed from the lower water to the upper water through the sand layer. In particular, the as-prepared micromotors demonstrated optimal efficiency in pollutant removal, with an adsorption kinetic coefficient exceeding five times that of the micromotors only possessing micropores and mesopores. This novel strategy fabricating Janus-micromotors shows great potential for efficient treatment in complex environments.

3.
Small ; : e2311249, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38482932

RESUMO

Host-guest catalyst provides new opportunities for targeted applications and the development of new strategies for preparing host-guest catalysts is highly desired. Herein, an in situ solvent-free approach is developed for implanting ZrW2 O7 (OH)2 (H2 O)2 nanorods (ZrW-NR) in nitro-functionalized UiO-66(Zr) (UiO-66(Zr)-NO2 ) with hierarchical porosity, and the encapsulation of ZrW-NR enables the as-prepared host-guest catalyst remarkably enhanced catalytic performance for both for oxidative desulfurization (ODS) and acetalization reactions. ZrW-NR@UiO-66(Zr)-NO2 can eliminate 500 ppm sulfur within 9 min at 40 °C in ODS, and can transform 5.6 mmol benzaldehyde after 3 min at room temperature in acetalization reaction. Its turnover frequencies reach 72.3 h-1 at 40 °C for ODS which is 33.4 times higher than UiO-66(Zr)-NO2 , and 28140 h-1 for acetalization which is the highest among previous reports. Density functional theory calculation result indicates that the W sites in ZrW-NR can decompose H2 O2 to WVI -peroxo intermediates that contribute to catalytic activity for the ODS reaction. This work opens a new solvent-free approach for preparing MOFs-based host-guest catalysts to upgrade their redox and acid performance.

4.
BMC Microbiol ; 24(1): 269, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39030474

RESUMO

Candida auris (C. auris) is a yeast that has caused several outbreaks in the last decade. Cell wall chitin plays a primary role in the antifungal resistance of C. auris. Herein, we investigated the potential of chitinase immobilized with UiO-66 to act as a potent antifungal agent against C. auris. Chitinase was produced from Talaromyces varians SSW3 in a yield of 8.97 U/g dry substrate (ds). The yield was statistically enhanced to 120.41 U/g ds by using Plackett-Burman and Box-Behnken design. We synthesized a UiO-66 framework that was characterized by SEM, TEM, XRD, FTIR, a particle size analyzer, and a zeta sizer. The produced framework had a size of 70.42 ± 8.43 nm with a uniform cubic shape and smooth surface. The produced chitinase was immobilized on UiO-66 with an immobilization yield of 65% achieved after a 6 h loading period. The immobilization of UiO-66 increased the enzyme activity and stability, as indicated by the obtained Kd and T1/2 values. Furthermore, the hydrolytic activity of chitinase was enhanced after immobilization on UiO-66, with an increase in the Vmax and a decrease in the Km of 2- and 38-fold, respectively. Interestingly, the antifungal activity of the produced chitinase was boosted against C. auris by loading the enzyme on UiO-66, with an MIC50 of 0.89 ± 0.056 U/mL, compared to 5.582 ± 0.57 U/mL for the free enzyme. This study offers a novel promising alternative approach to combat the new emerging pathogen C. auris.


Assuntos
Antifúngicos , Candida auris , Quitinases , Testes de Sensibilidade Microbiana , Nanopartículas , Quitinases/farmacologia , Quitinases/metabolismo , Quitinases/química , Antifúngicos/farmacologia , Antifúngicos/química , Nanopartículas/química , Candida auris/efeitos dos fármacos , Candida auris/genética , Enzimas Imobilizadas/química , Talaromyces/efeitos dos fármacos , Talaromyces/química , Talaromyces/enzimologia , Farmacorresistência Fúngica Múltipla , Hidrólise , Quitina/química , Quitina/farmacologia
5.
Chemistry ; 30(12): e202302731, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38227358

RESUMO

The Zr-based Metal Organic Framework (MOF) UiO-66(Zr) is widely employed owing to its good thermal and chemical stabilities. Although the long-range structure of this MOF is preserved in the presence of water during several days, little is known about the formation of defects, which cannot be detected using diffraction techniques. We apply here 17 O solid-state NMR spectroscopy at 18.8 T to investigate the reactivity of UiO-66, through the exchange of oxygen atoms between the different sites of the MOF and water. For that purpose, we have selectively enriched in 17 O isotope the carboxylate groups of UiO-66(Zr) by using it with 17 O-labeled terephthalic acid prepared using mechanochemistry. In the presence of water at 50 °C and a following dehydration at 150 °C, we observe an overall exchange of O atoms between COO- and µ3 -O2- sites. Furthermore, we demonstrate that the three distinct oxygen sites, µ3 -OH, µ3 -O2- and COO- , of UiO-66(Zr) MOF can be enriched in 17 O isotope by post-synthetic hydrothermal treatment in the presence of 17 O-enriched water. These results demonstrate the lability of Zr-O bonds and the reactivity of UiO-66(Zr) with water.

6.
J Nanobiotechnology ; 22(1): 99, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38461229

RESUMO

The Influenza A virus (IAV) is a zoonotic pathogen that infects humans and various animal species. Infection with IAV can cause fever, anorexia, and dyspnea and is often accompanied by pneumonia characterized by an excessive release of cytokines (i.e., cytokine storm). Nanodrug delivery systems and nanoparticles are a novel approach to address IAV infections. Herein, UiO-66 nanoparticles (NPs) are synthesized using a high-temperature melting reaction. The in vitro and in vivo optimal concentrations of UiO-66 NPs for antiviral activity are 200 µg mL-1 and 60 mg kg-1, respectively. Transcriptome analysis revealed that UiO-66 NPs can activate the RIG-I-like receptor signaling pathway, thereby enhancing the downstream type I interferon antiviral effect. These NPs suppress inflammation-related pathways, including the FOXO, HIF, and AMPK signaling pathways. The inhibitory effect of UiO-66 NPs on the adsorption and entry of IAV into A549 cells is significant. This study presents novel findings that demonstrate the effective inhibition of IAV adsorption and entry into cells via UiO-66 NPs and highlights their ability to activate the cellular RIG-I-like receptor signaling pathway, thereby exerting an anti-IAV effect in vitro or in mice. These results provide valuable insights into the mechanism of action of UiO-66 NPs against IAV and substantial data for advancing innovative antiviral nanomedicine.


Assuntos
Vírus da Influenza A , Influenza Humana , Estruturas Metalorgânicas , Infecções por Orthomyxoviridae , Ácidos Ftálicos , Camundongos , Humanos , Animais , Infecções por Orthomyxoviridae/tratamento farmacológico , Transdução de Sinais , Antivirais/farmacologia , Antivirais/uso terapêutico
7.
Mikrochim Acta ; 191(6): 304, 2024 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-38710810

RESUMO

Dual-emissive fluorescence probes were designed by integrating porphyrin into the frameworks of UiO-66 for ratiometric fluorescence sensing of amoxicillin (AMX). Porphyrin integrated UiO-66 showed dual emission in the blue and red region. AMX resulted in the quenching of blue fluorescence component, attributable to the charge neutralization and hydrogen bonds induced energy transfer. AMX was detected using (F438/F654) as output signals. Two linear relationships were observed (from 10 to 1000 nM and 1 to 100 µM), with a limit of detection of 27 nM. The porphyrin integrated UiO-66 probe was used to detect AMX in practical samples. This work widens the road for the development of dual/multiple emissive fluorescence sensors for analytical applications, providing materials and theoretical supporting for food, environmental, and human safety.


Assuntos
Amoxicilina , Antibacterianos , Corantes Fluorescentes , Leite , Porfirinas , Espectrometria de Fluorescência , Leite/química , Porfirinas/química , Antibacterianos/análise , Antibacterianos/química , Amoxicilina/análise , Amoxicilina/química , Corantes Fluorescentes/química , Animais , Espectrometria de Fluorescência/métodos , Limite de Detecção , Estruturas Metalorgânicas/química , Resíduos de Drogas/análise , Contaminação de Alimentos/análise
8.
Mikrochim Acta ; 191(4): 188, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38457047

RESUMO

A solid-phase microextraction (SPME) Arrow and high-performance liquid chromatography-UV detector (HPLC-UV, detection at 225 nm) based method was developed for the selective determination of nine alkylphenols (APs) in milk. The functionalized mesoporous UiO-66 (4-meso-UiO-66) was utilized as the new coating material, which was synthesized by post-modification of pore-expanded UiO-66-NH2 by an esterification reaction with 4-pentylbenzoic acid. It was fully characterized by X-ray photoelectron spectroscopy (XPS), fourier transformation infrared spectrometry, nitrogen sorption-desorption test, scanning electron microscopy, transmission electron microscopy, and X-ray diffractometer. The characterization results showed the ester groups and benzene rings were introduced into the 4-meso-UiO-66, and the mesoporous structure was predominant in the 4-meso-UiO-66. The extraction mechanism of 4-meso-UiO-66 to APs is the synergistic effect of Zr-O electrostatic interaction and the size exclusion effect resulting from XPS, selectivity test, and nitrogen sorption-desorption test. The electrospinning technique was utilized to fabricate the 4-meso-UiO-66 coated SPME Arrow and polyacrylonitrile (PAN) was used as the adhesive. The mass rate of 4-meso-UiO-66 to PAN and the electrospinning time were evaluated. The extraction and desorption parameters were also studied. The linear range of this method was 0.2-1000 µg L-1 with a coefficient of determination greater than 0.9989 under the optimal conditions. The detection limits were 0.05-1 µg L-1, the inter-day and intra-day precision (RSD) were 2.8-11.5%, and the recovery was 83.6%-112%. The reusability study showed that the extraction performance of this new SPME Arrow could be maintained after 80 adsorption-desorption cycles. This method showed excellent applicability for the selective determination of APs in milk.

9.
Nano Lett ; 23(5): 1787-1793, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36802605

RESUMO

Atomically dispersed metals encapsulated in metal-organic frameworks (MOFs) have attracted extensive attention in catalysis and energy fields. Amino groups were considered conducive to the formation of single atom catalysts (SACs) due to the strong metal-linker interactions. Here, atomic details of Pt1@UiO-66 and Pd1@UiO-66-NH2 are revealed using low-dose integrated differential phase contrast scanning transmission electron microscopy (iDPC-STEM). Single Pt atoms locate on the benzene ring of p-benzenedicarboxylic acid (BDC) linkers in Pt@UiO-66, while single Pd atoms are adsorbed by the amino groups in Pd@UiO-66-NH2. However, Pt@UiO-66-NH2 and Pd@UiO-66 show obvious clusters. Therefore, amino groups do not always favor the formation of SACs, and density functional theory (DFT) calculations indicate that a moderate binding strength between metals and MOFs is preferred. These results directly reveal the adsorption sites of single metal atoms in UiO-66 family, paving the way for understanding the interaction between single metal atoms and the MOFs.

10.
Int J Mol Sci ; 25(12)2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38928488

RESUMO

The oxidative esterification of aldehydes under mild conditions remains a significant challenge. This study introduces a unique defective UiO-66 to achieve gold nanoclusters (AuNCs) for efficient aldehyde oxidation under mild conditions. The construction and characterization of these materials are thoroughly investigated by techniques of XRD, SEM and TEM images, FT-IR, Raman, and XPS spectrum, emphasizing the unique microporous in defective UiO-66 are conducive to the fabrication of AuNCs. The catalytic performance of the prepared materials in aldehyde oxidation reactions is systematically evaluated, demonstrating the remarkable efficiency of dispersed Au@UiO-66-25 with high-content (9.09 wt%) Au-loading and ultra-small size (~2.7 nm). Moreover, mechanistic insights into the catalytic process under mild conditions (70 °C for 1 h) are provided, elucidating the determination of defective UiO-66 in the confined fabrication of AuNCs and subsequent furfural adsorption, which underlie the principles governing the observed enhancements. This study establishes the groundwork for the synthesis of highly dispersed and catalytically active metal nanoparticles using defective MOFs as a platform, advancing the catalytic esterification reaction of furfural to the next level.


Assuntos
Aldeídos , Ouro , Nanopartículas Metálicas , Oxirredução , Ouro/química , Nanopartículas Metálicas/química , Aldeídos/química , Catálise , Estruturas Metalorgânicas/química , Porosidade , Esterificação , Espectroscopia de Infravermelho com Transformada de Fourier
11.
J Environ Manage ; 366: 121868, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39032257

RESUMO

The Fenton reaction is recognized as an effective technique for degrading persistent organic pollutants, such as the emerging pollutant trimethoprim (TMP). Recently, due to the excellent reducibility of active hydrogen ([H]), Pd-H2 has been preferred for Fenton-like reactions and the specific H2 activation of Pd-based catalysts. Herein, a heterogeneous Fenton catalyst named the hydrogen-accelerated oxygen reduction Fenton (MHORF@UiO-66(Zr)) system was prepared through the strategy of building ships in the bottle. The [H] has been used for the acceleration of the reduction of Fe(III) and self-generate H2O2. The systematic characterization demonstrated that the nano Pd0 particle was highly dispersed into the UiO-66(Zr). The results found that 20 mg L-1 of TMP was thoroughly degraded within 90 min in the MHORF@UiO-66(Zr) system under conditions of initial pH 3, 30 mL min-1 H2, 2 g L-1 Pd@UiO-66(Zr) and 25 µM Fe2+. The hydroxyl radical as well as the singlet oxygen were evidenced to be the main reactive oxygen species by scavenging experiments and electron spin resonance. In addition, both reducing Fe(III) and self-generating H2O2 could be achieved due to the strong metal-support interaction (SMSI) between the nano Pd0 particles and UiO-66(Zr) confirmed by the correlation results of XPS and calculation of density functional theory. Finally, the working mechanism of the MHORF@UiO-66(Zr) system and the possible degradation pathway of the TMP have been proposed. The novel system exhibited excellent reusability and stability after six cyclic reaction processes.

12.
Molecules ; 29(11)2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38893383

RESUMO

The thermally stable zirconium-based MOF, UiO-66, was employed for the preparation of bonded porous-layer open-tubular (PLOT) GC columns. The synthesis included the in situ growth of the UiO-66 film on the inner wall of the capillary through a one-step solvothermal procedure. SEM-EDX analysis revealed the formation of a thin, continuous, uniform, and compact layer of UiO-66 polycrystals on the functionalized inner wall of the column. The average polarity (ΔIav = 700) and the McReynolds constants reflected the polar nature of the UiO-66 stationary phase. Several mixtures of small organic compounds and real samples were used to evaluate the separation performance of the fabricated columns. Linear alkanes from n-pentane to n-decane were baseline separated within 1.35 min. Also, a series of six n-alkylbenzenes (C3-C8) were separated within 3 min with a minimum resolution of 3.09, whereas monohalobenzene mixtures were separated at 220 °C within 14s. UiO-66 PLOT columns are ideally suited for the isothermal separation of chlorobenzene structural isomers at 210 °C within 45 s with Rs ≥ 1.37. The prepared column featured outstanding thermal stability (up to 450 °C) without any observed bleeding or significant impact on its performance. This feature enabled the analysis of various petroleum-based samples.

13.
J Environ Sci (China) ; 139: 556-568, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38105076

RESUMO

The coupling of washing with adsorption process can be adopted for the treatment of soils contaminated with heavy metals pollution. However, the complex environment of soil and the competitive behavior of leaching chemicals considerably restrain adsorption capacity of adsorbent material during washing process, which demands a higher resistance of the adsorbents to interference. In this study, we synthesized strongly magnetic, high specific surface area (573.49 m2/g) UiO66 composites (i.e., UiO66-Fe3O4) using hydrothermal process. The UiO66-Fe3O4 was applied as an adsorbent during the ethylene diamine tetraacetic acid (EDTA)-assisted washing process of contaminated soil. The incorporation of UiO66-Fe3O4 results in rapid heavy metal removal and recovery from the soil under low concentrations of washing agent (0.001 mol/L) with reduced residual heavy metal mobility of soil after remediation. Furthermore, UiO66-Fe3O4 can quickly recollect by an external magnet, which offers a simple and inexpensive recovery method for heavy metals from contaminated soil. Overall, UiO66-Fe3O4 configuration with EDTA-assisted washing process showed opportunities for heavy metals contaminated sites.


Assuntos
Poluentes Ambientais , Recuperação e Remediação Ambiental , Metais Pesados , Poluentes do Solo , Ácido Edético , Solo , Adsorção , Poluentes do Solo/análise , Metais Pesados/análise
14.
Angew Chem Int Ed Engl ; 63(15): e202319894, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38265268

RESUMO

Membrane-based separation has the merit of low carbon footprint. In this study, the pore size of metal-organic framework (MOF) membranes is rationally designed for discriminating various pairs of hydrocarbon isomers. Specifically, Zr-MOF UiO-66 (UiO stands for University of Oslo) membranes are developed for separating p/o-xylene due to their proper pore size. For n-hexane/2-methylpentane separation, the functional groups and proportion of the ligands in UiO-66 are gradually adjusted to effectively regulate the pore size, and UiO-66-33Br membranes are constructed. In addition, relying on the utilization of ligands with shorter length, MOF-801 membranes with smaller pore size are fabricated for n/i-butane separation.

15.
Small ; 19(28): e2300076, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37029708

RESUMO

Polysulfides huttling and interfacial instability of Lithium-anode are the main technical issues hindering commercialization of high-energy-density lithium-sulfur batteries. Simply addressing the problem of polysulfide shuttling or lithium dendrite growth can result in safety hazards or short lifespan. To synchronously tackle the aforementioned issues, the authors have designed an asymmetric cellulose gel electrolyte, a defective and ionized UiO66/black phosphorus heterostructure coating layer (Di-UiO66/BP) and a cationic cellulose gelelectrolyte (QACA). Defective and ionized engineered UiO66 particles significantly enhances performance of UiO66/BP layer in anchoring free polysulfides, promoting smooth and effective polysulfide conversion and expediting the redox kinetics of sulfur cathode, therefore suppressing polysulfide shuttling. QACA electrolyte with numerous cationic groups can interact with anions via electrostatic adsorption, thus enhancing lithium-ion transference number and contributing to formation of stable solid electrolyte interface to suppress lithium dendrite growth. Owing to the superior performance of QACA/Di-UiO66/BP, the final cells exhibit outstanding electrochemical performance, presenting high sulfur utilization (1420.1 mAh g-1 at 0.1 C), high-rate capacity (665.4 mAh g-1 at 4 C) and long cycle lifespan. This work proposes a strategy of designing asymmetric electrolytes to simultaneously address the challenges in both S-cathode and Li-anode, which contributes to advanced Li-S batteries and their practical application.

16.
Small ; 19(45): e2302692, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37469019

RESUMO

This study presents a novel approach to decontaminate ferrocyanide-contaminated wastewater. The work effectively demonstrates the use of bimetallic Mo/Zr-UiO-66 as a super-adsorbent for rapid sequestration of Prussian blue, a frequently found iron complex in cyanide-contaminated soils/groundwater. The exceptional performance of Mo/Zr-UiO-66 is attributed to the insertion of secondary metallic sites, which deliver synergistic effects, benefiting the inherent qualities of the framework. Moreover, to extend the industrial applications of metal-organic frameworks (MOFs) in real-world scenarios, an approach is delivered to structure the nanocrystalline powders into MOF-based macrostructures. The work demonstrates an interfacial process to develop continuous MOF nanostructures on ordinary laboratory-grade filter papers. The novelty of the work lies in the development of robust free-standing filtration materials to purify PB dye-contaminated water. Additionally, the work embraces a circular economy concept to address problems related to resource scarcity, excessive waste production, and maintenance of economic benefits. Consequently, the PB dye-loaded adsorbent waste is re-employed for the adsorption of heavy metals (Pb2+ and Cd2+ ). Simultaneously, the study aims to address the problems related to the real-time handling of powdered adsorbents, and the generation of ecologically harmful secondary waste, thereby, progressing toward a more sustainable system.

17.
Small ; 19(38): e2301035, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37226376

RESUMO

Stable platforms of host-guest catalysts are indispensable in the field of heterogeneous catalysis, however, clarifying the specific effect of host remains challenging. Herein, polyoxometalate (POM) is encapsulated in three types of UiO-66(Zr) with different controlled densities of defects by the aperture opening and closing strategy at ambient-temperature. It is found that catalytic activity of POM for oxidative desulfurization (ODS) at room temperature is turned on when encapsulated in the defective UiO-66(Zr), and the sulfur oxidation efficiency shows an obvious increasing trend (from 0.34 to 10.43 mmol g-1 h-1 ) with the increased concentration of defects in UiO-66(Zr) host. The as-prepared catalyst with the most defective host displays ultrahigh performance which removed 1000 ppm sulfur with exceptionally diluted oxidant at room-temperature within 25 min. The turnover frequency can reach 620.0 h-1 at 30 °C, which surpassed all the reported MOFs based ODS catalysts. A substantial guest/host synergistic effect mediated by the defective sites in UiO-66(Zr) is responsible for the enhancement. Density functional theory calculations reveal that OH/OH2 capped on the open Zr sites of host UiO-66(Zr) can decompose H2 O2 to OOH group and enables the formation of WVI -peroxo intermediates that determine the ODS activity.

18.
Small ; 19(20): e2207198, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36799195

RESUMO

Efficient nitric oxide (NO) removal without nitrogen dioxide (NO2 ) emission is desired for the control of air pollution. Herein, a series of (Zr/Ti)UiO-66-NH2 with congenetic shell-core structure, denoted as Ti-UION, are rapidly synthesized by microwave-assisted post-synthetic modification for NO removal. The optimal Ti-UION (i.e., 2.5Ti-UION) exhibits the highest activity of 80.74% without NO2 emission with moisture, which is 21.65% greater than that of the UiO-66-NH2 . The NO removal efficiency of 2.5Ti-UION further increases to 95.92% without photocatalyst deactivation under an anhydrous condition. This is because selectively produced NO2 in photocatalysis is completely adsorbed into micropores, refreshing active sites for subsequent reaction. In addition, the enhanced photocatalytic activity after Ti substitution is due to the presence of Ti electron acceptor, the potential difference between the shell and core of Ti-UION crystal, and the high conductivity of TiO units. Additionally, the improved adsorption of gas molecules not only favors NO oxidation, but also avoids the emission of NO2 . This work provides a feasible strategy for rapid metal substitution in metal-organic frameworks and insights into enhanced NO photodegradation.

19.
Chemistry ; 29(1): e202202625, 2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36152311

RESUMO

Hydrogenation of multiple bonds are among the most general and important organic reactions. Typical heterogeneous catalysts are based on transition metal nanoparticles, including noble metals. Data are presented here showing that metal nodes of MIL-101(Cr) and UiO-66 in the absence of occluded metal nanoparticles can promote hydrogenation of polarized X=Y double bonds of nitro and carbonyl groups. The catalytic activity is a function of the composition of the metal node and the organic linker. It is proposed that the reaction mechanism is based on the operation of frustrated Lewis acid/base pairs.

20.
Nanotechnology ; 34(13)2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36571850

RESUMO

Fe3O4is an environmentally friendly gas sensing material with high response, but the cross-response to various analytes and poor thermal stability limit its practical applications. In this work, we prepared Fe3O4@uio66 core-shell composite via a facile method. The selective response to volatile organic compounds, especially to electrolyte vapors of lithium-ion batteries, as well as long-term stability of Fe3O4@uio66 has been dramatically enhanced compared to pure Fe3O4, due to the preconcentrator feature and thermal stability of the uio66 thin shell. Real-time detection of electrolyte leakage for an actual punctured lithium-ion battery was further demonstrated. The Fe3O4@uio66 sensor, after aging for 3 months, was able to detect the electrolyte leakage in 30 s, while the voltage of the punctured battery was maintained at the same level as that of a pristine battery over 6 h. This practical test results verified ability of the Fe3O4@uio66 sensor with long-term aging stability for hours of early safety warning of lithium-ion batteries.

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