Zirconium-organic Framework Research Articles

Nanosized Zirconium-Organic Frameworks with Redox Behaviors for the Switchable Detection of Hypochlorous Acid and Ascorbic Acid.

Luminescent metal-organic frameworks (LMOFs) exhibit promising applications as chemical sensors, especially for organic-linker-based LMOFs due to their unlimited structures and pre- and postfunctionality. However, it is still a challenge to introduce specific functional groups into LMOFs as reaction sites for sensing. Herein, a new luminescent zirconium-based metal-organic framework (Zr-MOF), HIAM-4009L, is reported with csq underlying net. By integrating the hydroquinone moiety into the skeleton of the organic linker via the reaction between o-diamine and aldehydes, nanosized HIAM-4009L exhibits reversible emission responses toward hypochlorous acid (HClO) and l-ascorbic acid (vitamin C, Vc) due to the switchable hydroquinone/quinone reaction. This nano-MOF can be used as a reaction-based chemical sensor for HClO and Vc detection with high selectivity and sensitivity. The present work not only provides nanosized MOFs for the reversible detection of HClO and Vc but also sheds light on the rational design of LMOFs with specific functional groups using an o-diamine- and aldehyde-based reaction.

Exploiting Cross‐Responsiveness of Fluorescent Interpenetrated Zirconium–Organic Frameworks Integrated in Polymeric Membranes as a Multi‐Analyte Gas Sensor Array (Advanced Optical Materials 30/2024)

Exploiting Cross‐Responsiveness of Fluorescent Interpenetrated Zirconium–Organic Frameworks Integrated in Polymeric Membranes as a Multi‐Analyte Gas Sensor Array (Advanced Optical Materials 30/2024)

Full-Color Emissive Zirconium-Organic Frameworks Constructed via in situ "One-Pot" Single-Site Modification for Tryptophan Detection and Energy Transfer.

Organic linker-based luminescent metal-organic frameworks (LMOFs) have received extensive studies due to the unlimited species of emissive organic linkers and tunable structure of MOFs. However, the multiple-step organic synthesis is always a great challenge for the development of LMOFs. As an alternative strategy, in situ "one-pot" strategy, in which the generation of emissive organic linkers and sequential construction of LMOFs happen in one reaction condition, can avoid time-consuming pre-synthesis of organic linkers. In the present work, we demonstrate the successful utilization of in situ "one-pot" strategy to construct a series of LMOFs via the single-site modification between the reaction of aldehydes and o-phenylenediamine-based tetratopic carboxylic acid. The resultant MOFs possess csq topology with emission covering blue to near-infrared. The nanosized LMOFs exhibit excellent sensitivity and selectivity for tryptophan detection. In addition, two component-based LMOFs can also be prepared via the in situ "one-pot" strategy and used to study energy transfer. This work not only reports the construction of LMOFs with full-color emissions, which can be utilized for various applications, but also indicates that in situ "one-pot" strategy indeed is a useful and powerful method to complement the traditional MOFs construction method for preparing porous materials with tunable functionalities and properties.

Preparation of Zirconium-Based MOF-Derived Phosphide on GO/MXene Double Substrates for High-Performance Asymmetric Supercapacitors.

At present, it is very necessary to select and prepare suitable positive and negative electrode materials to fabricate high-performance asymmetric supercapacitors. Metal-organic frameworks (MOFs) have garnered significant attention in the energy storage field due to their high conductivity. As a branch, the zirconium organic framework (UIO-66) is a promising porous material due to its large specific surface area and abundant Zr centers. Graphene oxide (GO) and MXene are very suitable as substrate materials for conducting an MOF due to their abundant active sites and adjustable interlayer distance. The GO/MXene@NiZrP prepared through an in situ composite of GO and Mxene with the hydrothermal method and calcining method showed excellent electrochemical performance. Compared with the precursor UIO-66, the specific capacitance of the final product GO/MXene@NiZrP increases more than ten times, mainly because of its special layered porous structure, and GO/MXene@NiZrP has a larger specific surface area, pore volume, and surface defects caused by unstable Zr4+ than those of UIO-66. Using GO/MXene@NiZrP as the positive electrode and biochar (BC) as the negative electrode, an asymmetric supercapacitor, BC//GO/MXene@NiZrP, is assembled. After 10,000 cycles at a current density of 10 A g-1, the capacitance retention remains at 83.3%, showing excellent cycle stability.

Exploiting Cross‐Responsiveness of Fluorescent Interpenetrated Zirconium–Organic Frameworks Integrated in Polymeric Membranes as a Multi‐Analyte Gas Sensor Array

Exploiting Cross‐Responsiveness of Fluorescent Interpenetrated Zirconium–Organic Frameworks Integrated in Polymeric Membranes as a Multi‐Analyte Gas Sensor Array

Reticular Chemistry Directed "One-Pot" Strategy to in situ Construct Organic Linkers and Zirconium-Organic Frameworks.

Zirconium-based metal-organic frameworks (Zr-MOFs) have emerged as one of the most studied MOFs due to the unlimited numbers of organic linkers and the varying Zr-oxo clusters. However, the synthesis of carboxylic acids, especially multitopic carboxylic acids, is always a great challenge for the discovery of new Zr-MOFs. As an alternative approach, the in situ "one-pot" strategy can address this limitation, where the generation of organic linkers from the corresponding precursors and the sequential construction of MOFs are integrated into one solvothermal condition. Herein, inspired by benzimidazole-contained compounds synthesized via reaction of aldehyde and o-phenylenediamine, tri-, tetra-, penta- and hexa-topic carboxylic acids and a series of corresponding Zr-MOFs can be prepared via the in situ "one-pot" method under the same solvothermal conditions. This strategy can be utilized not only to prepare reported Zr-MOFs constructed using benzimidazole-contained linkers, but also to rationally design, construct and realize functionalities of zirconium-pentacarboxylate frameworks guided by reticular chemistry. More importantly, in situ "one-pot" method can facilitate the discovery of new Zr-MOFs, such as zirconium-hexacarboxylate frameworks. The present study demonstrates the promising potential of benzimidazole-inspired in situ "one-pot" approach in the crystal engineering of structure- and property-specific Zr-MOFs, especially with the guidance of reticular chemistry.

Solid-state 13C-NMR spectroscopic determination of side-chain mobilities in zirconium-based metal–organic frameworks

Abstract. Porous interpenetrated zirconium–organic frameworks (PIZOFs) are a class of Zr-based metal–organic frameworks (MOFs) which are composed of long, rod-like dicarboxylate linkers and Zr6O4(OH)4(O2C)12 nodes. Long oligoethylene glycol or aliphatic side chains are covalently attached to the linker molecules in the cases of PIZOF-10 and PIZOF-11, respectively. These side chains are supposedly highly mobile, thus mimicking a solvent environment. It is anticipated that such MOFs could be used as a solid catalyst – the MOF – with pore systems showing properties similar to a liquid reaction medium. To quantify the side-chain mobility, here we have applied different 1D and 2D NMR solid-state spectroscopic techniques like cross-polarization (CP) and dipolar-coupling chemical-shift correlation (DIPSHIFT) studies. The rather high 1H-13C CP efficiency observed for the CH2 groups of the side chains indicates that the long side chains are unexpectedly immobile or at least that their motions are strongly anisotropic. More detailed information about the mobility of the side chains was then obtained from DIPSHIFT experiments. Analytical expressions for elaborate data analysis are derived. These expressions are used to correlate order parameters and to slow motional rates with signals in indirect spectral dimensions, thus enabling the quantification of order parameters for the CH2 groups. The ends of the chains are rather mobile, whereas the carbon atoms close to the linker are more spatially restricted in mobility.

Local protons enhance photocatalytic CO2 reduction by porphyrinic zirconium-organic frameworks

MOF-OH with a large number of local proton sources not only modifies the microenvironment but also enables efficient charge separation, which thus exhibited effective CO2 capture and CO2 reduction under visible-light irradiation.

Highly Stable Amide-Functionalized Zirconium-Organic Frameworks: Synthesis, Structure, and Methane Storage Capacity.

With the development of crystalline porous materials toward methane storage, the stability issue of metal-organic framework (MOF) materials has caused great concern despite high working capacity. Considering the high stability of zirconium-based MOFs and effective functions of amide groups toward gas adsorption, herein, a series of UiO-66 type of Zr-MOFs, namely, Zr-fcu-H/F/CH3/OH, were successfully designed and synthesized by virtue of amide-functionalized dicarboxylate ligands bearing distinct side groups (i.e., -H, -F, -CH3, and -OH) and ZrCl4 in the presence of trifluoroacetic acid as the modulator. Single-crystal X-ray diffraction and topology analyses reveal that these compounds are archetypal fcu MOFs encompassing octahedral and tetrahedral cages, respectively. The N2 sorption isotherms and acid-base stability tests demonstrate that the materials possess not only relatively high surface areas, pore volumes, and appropriate pore sizes but also great hydrolytic stabilities ranging pH = 3-11. Furthermore, the volumetric methane storage working capacities of Zr-fcu-H, Zr-fcu-F, Zr-fcu-CH3, and Zr-fcu-OH at 298/273 K and 80 bar are 187/217, 175/193, 167/187, and 154/171 cm3 (STP) cm-3, respectively, which indicate that the zirconium-based crystalline porous materials are capable of storing relatively high amounts of methane.

Fabrication of biocompatible graphene oxide layered zirconium-organic frameworks entrapped magnetic bio-hybrid beads for defluoridation of water

Fluorine in the form fluoride is one the few elements that could cause healthiness trouble with together its insufficiency and surplus intake. For instance, the surplus fluoride in potable water leads to fluorosis. In this present study, magnetic iron oxide/graphene oxide/alginate/zirconium-organic frameworks (MGOAZ) based hybrid beads were fabricated and it was applied for defluoridation experiments. Several instrumental characterization techniques like EDAX, XPS, FTIR, SEM and XRD were studied to find the surface properties (physical and chemical) of fabricated MGOAZ beads material. Batch fluoride adsorption tests were performed to notice the fluoride adsorption action. The maximum defluoridation capacity (DC) of developed MGOAZ beads was attained at pH 7. Adsorption kinetics and isotherm equilibrium data for fluoride adsorption of the developed MGOAZ beads were vitally followed by pseudo-second-order/intraparticle and Langmuir isotherm model. Thermodynamic exploration exhibited that the adsorption route by MGOAZ beads was endothermic with spontaneous nature. Moreover, electrostatic attraction and complexation mechanism possess substantial role during fluoride adsorption onto the developed MGOAZ beads. Moreover, the regeneration performance and field suitability of MGOAZ beads was discussed in detail.

Terbium doping and energy level modification of zirconium organic frameworks as probes for the improved determination of histamine and visual inspection of food freshness

Food safety is a common concern among people, and the development of high-performance food freshness detection technology is crucial, but is still highly challenging. Fluorescent sensing based on metal organic frameworks is a promising technology to tackle this issue. In this work, three UiO-66 type Zirconium organic frameworks (ZrOFs) which are functionalized with varying numbers of hydroxyl groups to alter the energy levels, and partial replacement of Zirconium(IV) by Terbium(III) ions to introduce additional emitting centers, were explored as probes for the sensing of Histamine (His). With one hydroxyl group introduced, UiO-66-OH@Tb can be developed as ratiometric fluorescent probe with improved sensing performance, showing a wide detection range of 0 to 120 mg/L, and a low detection limit of 0.13 mg/L. UiO-66-OH@Tb can also be fabricated into composite film to function as visual sensing material of His. This work can provide instructions for the development of other fluorescent sensors.

Highly Efficient Photocatalytic Degradation of Tetracycline by Modifying UiO-66 via Different Regulation Strategies.

Wastewater containing organic pollutants cause potential harm to the environment and human health. A series of zirconium-organic frameworks (UiO-66) and their composites were synthesized by solvothermal methods, including band gap adjustment, heterojunction construction, and metal ion doping. For the model pollutant tetracycline (TC), all of the prepared catalysts could achieve effective degradation of it. Therein, the degradation efficiency of tetracycline could reach 95% under the UV irradiation with the aid of the catalyst, in which the UiO-66-NDC was modified with P-C3N4. The free radical capture experiments demonstrated that the superoxide radical (•O2-) was the main oxidizing species for the photodegradation of tetracycline. Hence, the improvement strategy of the catalyst would provide some enlightenment for the development of more efficient photocatalysts for the degradation of organic dyes in wastewater.

Topology and porosity control on zirconium–fumarate frameworks boosting xenon/krypton separation

AbstractThe designability and ultrahigh stability of zirconium–organic frameworks make them attractive adsorbents for noble gases xenon (Xe) and krypton (Kr), but their Xe/Kr separation performance needs to be further enhanced. In this study, we rationally control the topology and porosity of zirconium–fumarate frameworks by simply changing the synthesis conditions, and successfully construct an adsorbent (named as MIP‐203‐F) with one‐dimensional pore instead of the original cage‐like fcu metal–organic framework MOF‐801. The Xe/Kr separation performance of MIP‐203‐F is thoroughly evaluated by isotherm measurements and breakthrough experiments, while the adsorption mechanism is elucidated in detail by Monte Carlo and density functional theory calculations. Due to the uniform pore with suitable size and abundant polarization groups, MIP‐203‐F can differentially polarize and recognize atomic Xe/Kr gases, and establishes a new record among zirconium–organic frameworks for the capture and separation of Xe/Kr.

Coordination-Driven Self-Assembly of Schiff-Base-Tagged Ni–ZrO2/N–C Nanocatalysts for Selective Transformation of Renewable Methyl Levulinate

By functionalizing organic ligands and regulating metal nodes, metal–organic frameworks (MOFs) exhibit a variety of catalytic properties, which not only expand their application in biomass conversion but also increase the designability of catalysts. Herein, we have developed a synthesis strategy to fabricate multicomponent nanocatalysts (M–ZrO2/N–C, M = Ni, Fe, Co, Cu) derived from postsynthetic modification of zirconium–organic frameworks using Schiff base as an effective bridge. These nanocatalysts were utilized for the hydrogenation of bio-derived methyl levulinate to γ-valerolactone. The catalytic performance demonstrates that Ni–ZrO2/N–C possesses superior catalytic activity (99.9% conversion of methyl levulinate and 94.7% selectivity of γ-valerolactone), which could be attributed to the synergy effect of metal Ni and ZrO2 species. Various characterization methods (X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS)) indicated that metallic nickel activated H2, and the introduction of ZrO2 provided sufficient Lewis acid sites, accelerating the intramolecular esterification process.

Semirigid Highly Conjugated Zirconium-Organic Framework for the Capture of Micropollutants and Solar-Light Photodegradation.

Micro-organic pollutants, particularly organic dyes and personal care products (PPCPs), are widely present in wastewater, and thus pose a serious risk to human health. The capture and solar-light photodegradation of micro-organic pollutants are highly challenging tasks, which require the design and synthesis of microporous materials with specific structures. As we know, organic dyes and PPCPs can be absorbed via π-π* stacking. In this paper, an iron-based metal-organic framework (Fe-UiO-68-terNap) containing semirigid conjugated aromatic ligands is prepared for the capture and solar-light photodegradation of multiple water contaminants. UiO-68-terNap was synthesized based on ternaphthalene with π-π* stacking, which would increase the adsorption capacities of organic micropollutants in wastewater. Additionally, the formation of Fe-O-Zr enhances the charge-separation ability resulting in the successful degradation of micropollutants in 240 min. The novel material has been elucidated by single-crystal X-ray diffraction and Fe K-edge XANES, which provide key insights at a molecular level for the design of novel materials for the capture and photodegradation of organic micropollutants.

Cysteine-functionalization zirconium-organic framework for efficient adsorption 2,4-dichlorophenylacetic acid from water

2,4-Dichlorophenoxyacetic acid (2,4-D) is one of the most widely used pesticides in the world, which pose hazardous effects to the aquatic environment and human health due to its long-term and extensive use. In this work, MOF-808-Cys with highly water stable was prepared by one-pot method using L-cysteine modified Zr-based organic framework. Cysteine confers a variety of functional groups to MOF-808, enabling its chemical binding to the target substrate 2,4-dichlorophenylacetic acid (2,4-D). Adsorption experiments reveal that MOF-808-Cys has a higher adsorption efficiency (90%) toward 2,4-D than pristine MOF-808 (75%). Moreover, the adsorption kinetics confirms that the adsorption behavior follows a pseudo-second-order model with intraparticle diffusion. Experimental and characterization analysis show that physical adsorption and chemisorption synergistic improved adsorption capacity and adsorption efficiency. The -NH2 and -SH moiety are introduced into MOF-808 to enhance the adsorption performance by chemical adsorption. This study provides an effectively strategy of functional group modification to enhance the adsorption of pesticides and antibiotic pollutants in wastewater.

Aggregation-Induced Electrochemiluminescence Based on a Zinc-Based Metal-Organic Framework and a Double Quencher Au@UiO-66-NH2 for the Sensitive Detection of Amyloid β 42 via Resonance Energy Transfer.

A novel sandwich electrochemiluminescence (ECL) biosensor based on aggregation-induced electrochemiluminescence resonance energy transfer (AIECL-RET) was designed for the sensitive detection of amyloid β42 (Aβ42). The synthesized silver nanoparticle-functionalized zinc metal-organic framework (Ag@ZnPTC) and gold nanoparticle-functionalized zirconium organic framework (Au@UiO-66-NH2) were used as the ECL donor and acceptor, respectively. AgNPs were generated in situ on the surface of ZnPTC, which further improved the ECL intensity and the loading of antibody 1 (Ab1). Under the optimized experimental conditions, the linear detection range of Aβ42 concentration was 10 fg/mL to 100 ng/mL, and the detection limit was 2.4 fg/mL (S/N = 3). The recoveries of Aβ42 were 99.5-104%. The method has good stability, repeatability, and specificity. Ag@ZnPTC/Au@UiO-66-NH2 provides an assay for the sensitive detection of disease biomarkers.

Eu3+-anchoring Zirconium-organic framework for enhancing fluorescence sensing detection sensitivity towards Cr(VI) ions

Heavy metal ion Cr(VI) content has been regarded as one of the most important indicators for discharged industrial wastewater. However, effective identification and detection of Cr(VI) analytes with high sensitivity and selectivity from various water environments remains a significant challenge. In this study, a novel luminescent material (labelled as Eu@Zr-MOF) with high water stability was assembled by post-modification of a zirconium-organic framework with lanthanide Eu3+ ions. And the coordination bonds binding between Eu3+ ions and carboxyl O atoms of Zr-MOF were confirmed by XPS technique. After Eu3+ ions were successfully immobilized within the Zr-MOF lattice, Eu@Zr-MOF exhibits a bright red fluorescence signal which was inherited from the unique luminescent feature of embedded Eu3+ ions. Notably, Eu@Zr-MOF can be deployed as a reliable photochemical sensor for quantitative fluorescence quenching detection of Cr2O72− ions based on the emission peak at 618 nm, showing rather high sensitivity (KSV = 6.746 × 104 M−1) and ultra low detection limit (DL = 5.71 ppb) which has been enhanced more than 3 times compared with pristine Zr-MOF. This study provides a reliable reference for the preparation of novel luminescent MOFs platform for efficient recognition and detection of Cr(VI) analytes.

Highly Sensitive Adsorption and Detection of Iodide in Aqueous Solution by a Post-Synthesized Zirconium-Organic Framework

Effective methods of detection and removal of iodide ions (I-) from radioactive wastewater are urgently needed and developing them remains a great challenge. In this work, an Ag+ decorated stable nano-MOF UiO-66-(COOH)2 was developed for the I- to simultaneously capture and sense in aqueous solution. Due to the uncoordinated carboxylate groups on the UiO-66-(COOH)2 framework, Ag+ was successfully incorporated into the MOF and enhanced the intrinsic fluorescence of MOF. After adding iodide ions, Ag+ would be produced, following the formation of AgI. As a result, Ag+@UiO-66-(COOH)2 can be utilized for the removal of I- in aqueous solution, even in the presence of other common ionic ions (NO2-, NO3-, F-, SO42-). The removal capacity as high as 235.5 mg/g was calculated by Langmuir model; moreover, the fluorescence of Ag+@UiO-66-(COOH)2 gradually decreases with the deposition of AgI, which can be quantitatively depicted by a linear equation. The limit of detection toward I- is calculated to be 0.58 ppm.

A zirconium–organic framework nanosheet-based aptasensor with outstanding electrochemical sensing performance

The as-synthesized PCN-222(Fe) nanosheet can efficiently immobilize aptamers to fabricate an electrochemical aptasensor, which is used as an efficient platform for impedimetric sensing toward tobramycin. • A PCN-222(Fe) nanosheet is prepared successfully. • It can efficiently immobilize aptamers to fabricate an electrochemical aptasensor. • It is used as an efficiently impedimetric sensor toward tobramycin. A zirconium metal-organic framework nanosheet, namely PCN-222(Fe) NS, is prepared using [5,10,15,20-tetrakis(4-carboxyphenyl)porphyrinato]-Fe(III) chloride and Zr clusters, which is further investigated in detail by various technologies. The as-synthesized PCN-222(Fe) NS can efficiently immobilize aptamers to construct an electrochemical aptasensor for impedimetric sensing toward tobramycin (TOB). The fabricated electrochemical aptasensor can sensitively monitor TOB with outstanding specificity, fine long-term preservation, acceptable repeatability as well as good actual usability.