•Novel nano-probe Eu3+ post-functionalized MIL-53 (Al) is designed and prepared.•Fluorescent Probe can detect MG with high sensitivity and selectivity via FRET.•FRET process between MG and ...Eu3+-MIL-53 (Al) is revealed in detail.•Probe can instantaneous reusability after being cleaned with deionized water.•Probe was applied for sensing MG in aquaculture water and aquatic products.
An ingenious nanoscale fluorescent sensor derived from Eu3+-postfunctionalized MIL-53 (Al) (Eu3+@MIL-53 Al) was fabricated though a simple and effective approach. Malachite green (MG) effectively turned off the luminescence of Eu3+@MIL-53 (Al) via fluorescence resonance energy transfer (FRET), thus enabling MG sensing. The developed probe exhibited instantaneous reusability after being cleaned with deionized water. The fluorescence intensity, quenching efficiency, and crystal structure of the recoverable sensor after five recycling processes were unchanged compared with those of the original sample. Moreover, the potential mechanism of MG detection was revealed in detail. This work represents the first attempt to determine MG in aquaculture water and products by using metal–organic frameworks (MOFs). The Eu3+@MIL-53 (Al) probe proved to be a remarkable fluorescence probe for MG with high selectivity, sensitivity, and excellent regeneration capability. It provides a promising functional platform for the recognition of illegal MG addition to aquaculture water and products.
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•Significance and advantages of COFs for environmental remediation are discussed.•Synthesis and modification of COF-based materials are briefly described.•COF-derived materials ...including COF-derived carbons were also dealt.•The environmental remediation applications of COFs are discussed in detail.•The outcomes and future directions in synthesis and application are presented.
Covalent organic framework (COF) is a group of porous organic polymeric materials obtained from covalently attached organic building blocks. They exhibit positional control in two- or three-dimensional spaces through the predesigned and specified bonding of the monomer linkers. COFs are contemporary materials, and the recent identification of various synthesis and linking procedures has allowed their preparation with many advantageous properties and their usage in various applications. They can also be postsynthetically modified or converted to other materials of specific interest, thereby achieving materials with improved physical and chemical properties. COFs are considered as one of the most promising materials for applications in environmental remediation because of their ordered geometry, high porosity, functionality, high stability, and postsynthetic tunability in various physical and chemical forms. This review highlights the basic state-of-the-art in the advancement of stable COFs and their postsynthetic modification methods. The environmental remediation applications of COFs, which include adsorption, filtration, separation, catalysis, and sensing, will also be discussed in detail. Finally, the outcomes will be summarized and future directions will be discussed, indicating their promise for specialists in various research fields.
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•Tuning functional groups, not the physical structure, changes BPs adsorption on COFs.•A higher adsorption capacity and selectivity for BPF was observed on TpBD(NH2)2.•The adsorption ...of TpBD(NH2)2 was affected by electrostatic interactions.•TpBD(NO2)2 with hydrophobic interactions has conspicuous selectivity for BPC.•Hydrogen bonds are a critical factor affecting BPs adsorption on COFs.
Bisphenol analogues (BPs) are widely used as plasticizers and can be released during the aging and degradation of microplastics. Their persistence in water can cause serious harm to the ecosystem and human health. To improve the capture ability of COFs toward these estrogen-like toxins from water, amino group-functionalized COFs (COFs-TpBD(NH2)2) were constructed from nitro group COFs (COFs-TpBD(NO2)2) via the reduction of nitro to amino groups, and the adsorption behaviors for the five BPs (BPA, BPF, BPC, BPS and 4-CP) were compared. The focus was laid on the role of functional-group-tuning in the changes of adsorption capacity, selectivity and mechanisms of the COFs absorbents. The results showed that TpBD(NH2)2 has a higher adsorption capacity and better adsorption selectivity for most BPs than TpBD(NO2)2. COFs with nitro and amino groups show the best adsorption selectivity for BPC (KF = 6.71 min−1) and BPF (KF = 9.49 min−1), respectively. Chemisorption dominates the adsorption of the two COFs, and internal particle diffusion is the rate-determining step. The adsorption behavior difference between the two COFs was ascribed to the successful conversion of functional groups of the COFs from nitro to amino groups, which was proven by FT-IR, SEM, PXRD, and BET characterization results. Adsorption of BPA, BPC and BPF by TpBD(NO2)2 is positively related to hydrophobic interactions (represented by log Kow), but the adsorption mechanism of TpBD(NH2)2 was mainly attributed to the electrostatic interaction, as evidenced by the zeta potential and pKa. Hydrogen bonds were proven to be a critical factor that affects the adsorption of BPS and 4-CP by COFs. This study on the appropriate selection of COFs functional groups can provide insight into the future design of adsorbents and the prevention of BPs pollution release from microplastics.
Studies of proton conductive metal–organic frameworks (MOFs) have focused on increasing the charge carrier density. Of equal importance is the correlation of intrinsic properties (porosity and ...surface functionalization) of MOFs with conductivity. In their Communication on page 20173, Jihan Kim, Dae‐Woon Lim, Hiroshi Kitagawa et al. establish a correlation for proton conduction in MOFs with porosity and surface functionality. The confinement effect is essential for strengthening the hydrogen bonds leading to high proton conductivity.
Metal‐organic frameworks (MOFs) have been in the spotlight for a number of years due to their chemical and topological versatility. As MOF research has progressed, highly functionalised materials ...have become desirable for specific applications, and in many cases the limitations of direct synthesis have been realised. This has resulted in the search for alternative synthetic routes, with postsynthetic modification (PSM), a term used to collectively describe the functionalisation of pre‐synthesised MOFs whilst maintaining their desired characteristics, becoming a topic of interest. Advances in the scope of reactions performed are reported regularly; however reactions requiring harsh conditions can result in degradation of the framework. Zirconium‐based MOFs present high chemical, thermal and mechanical stabilities, offering wider opportunities for the scope of reaction conditions that can be tolerated, which has seen a number of successful examples reported. This microreview discusses pertinent examples of PSM resulting in enhanced properties for specific applications, alongside fundamental transformations, which are categorised broadly into covalent modifications, surface transformations, metalations, linker and metal exchange, and cluster modifications.
The chemical and mechanical stabilities of zirconium metal‐organic frameworks (MOFs) make them ideal platforms for postsynthetic modification. This microreview provides an overview of the various techniques for modification and the functionalities that can be incorporated into zirconium MOFs to facilitate different applications.
•N-Heterocyclic carbene (NHC) precursors-containing MOFs are reviewed.•Azolium linkers employed for synthesis of MOFs.•NHC precursors-containing MOFs accumulate the best characteristics from both NHC ...and MOFs.•Immobilization of the homogenous NHC complexes.•Post-synthetic modification of azolium-containing MOFs and their applications.
Metal–organic frameworks (MOFs) are coordination networks formed by self-assembly of metal ions or clusters and organic linkers. The functionalities and versatilities of MOF materials are enhanced by designing the frameworks with linkers, which have extra active functional groups that can be modified presynthetically, in situ, or postsynthetically. The carbenic carbon in N-heterocyclic carbenes enhances the potential of MOFs synthesized from azolium-containing linkers. In this review, we provide a survey and discussion of N-heterocyclic carbene precursor-containing MOFs and their various applications. This review will guide researchers and synthetic chemists attempting to design MOFs from N-heterocyclic carbene precursors.
This work reports the synthesis of pyridyltriazol-functionalized UiO-66 (UiO stands for University of Oslo), namely, UiO-66-Pyta, from UiO-66-NH
through three postsynthetic modification (PSM) steps. ...The good performance of the material derives from the observation that partial formylation (∼21% of -NHCHO groups) of H
BDC-NH
by DMF, as persistent impurity, takes place during the synthesis of the UiO-66-NH
. Thus, to enhance material performance, first, the as-synthesized UiO-66-NH
was deformylated to give pure UiO-66-NH
. Subsequently, the pure UiO-66-NH
was converted to UiO-66-N
with a nearly complete conversion (∼95%). Finally, the azide-alkyne3+2-cycloaddition reaction of 2-ethynylpyridine with the UiO-66-N
gave the UiO-66-Pyta. The porous MOF was then applied for the solid-phase extraction of palladium ions from an aqueous medium. Affecting parameters on extraction efficiency of Pd(II) ions were also investigated and optimized. Interestingly, UiO-66-Pyta exhibited selective and superior adsorption capacity for Pd(II) with a maximum sorption capacity of 294.1 mg g
at acidic pH (4.5). The limit of detection (LOD) was found to be 1.9 μg L
. The estimated intra- and interday precisions are 3.6 and 1.7%, respectively. Moreover, the adsorbent was regenerated and reused for five cycles without any significant change in the capacity and repeatability. The adsorption mechanism was described based on various techniques such as FT-IR, PXRD, SEM/EDS, ICP-AES, and XPS analyses as well as density functional theory (DFT) calculations. Notably, as a case study, the obtained UiO-66-Pyta after palladium adsorption, UiO-66-Pyta-Pd, was used as an efficient catalyst for the Suzuki-Miyaura cross-coupling reaction.
We demonstrate the successful functionalization of a porous aromatic framework for uranium extraction from water as exemplified by grafting PAF-1 with the uranyl chelating amidoxime group. The ...resultant amidoxime-functionalized PAF-1 (PAF-1-CH2AO) exhibits a high uranium uptake capacity of over 300 mg g–1 and effectively reduces the uranyl concentration from 4.1 ppm to less than 1.0 ppb in aqueous solutions within 90 min, well below the acceptable limit of 30 ppb set by the US Environmental Protection Agency. The local coordination environment of uranium in PAF-1-CH2AO is revealed by X-ray absorption fine structure spectroscopic studies, which suggest the cooperative binding between UO2 2+ and adjacent amidoxime species.
Mixed-matrix membranes (MMMs) formed by dispersing metal–organic framework (MOF) particles in polymers have attracted significant attention because these composite systems can potentially surpass the ...separation performance of pure polymers alone. However, performance improvements are often unrealized because of poor interfacial compatibility between the MOF and the polymer, which results in interfacial defects. From a practical perspective, strategies are needed to address these defects so that MMMs can be deployed in real-world separation processes. From a fundamental perspective, strategies are needed to reliably form defect-free MMMs so that transport models can be applied to estimate pure MOF property sets, thereby enabling the development of robust structure–property relationships. To address these interfacial challenges, we have developed a method to surface-functionalize a UiO-66-NH2 MOF with a nanoscopic shell of covalently tethered 4,4′-(hexafluoroisopropylidene)diphthalic anhydride–Durene oligomers. When combined with a high-molecular-weight polymer of identical chemical structure to that of the imide-functional MOF surface, defect-free MMMs with uniform particle dispersions can be formed. With this technique, both permeabilities and selectivities of select gases in the MMMs were improved at loadings ranging from 5 to 40 wt %. At a 40 wt % loading, CO2 permeability and CO2/CH4 selectivity were enhanced by 48 and 15%, respectively. Additionally, pure MOF permeabilities for H2, N2, O2, CH4, and CO2 were predicted by the Maxwell model.
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•ZIF-90 nanoparticles with different particle sizes were synthesized.•pH- and α-amylase-responsive nanocarriers were successfully prepared.•β-CD-NH2 surface coating reduced the ...photodegradation of indoxacarb.•IDC@ZIF-90-CD was able to disrupt the intestinal cells of red imported fire ants.•IDC@ZIF-90-CD affected amino acid metabolic pathways in red imported fire ants.
The invasion area of red imported fire ants (RIFAs) in China continues to expand due to factors such as ecological changes and human activities, and the resulting damage is becoming increasingly severe. The development of smart nanopesticides that respond to environmental stimuli response with precisely controlled release has great potential in improving insecticidal effects. In this work, a smart pH and α-amylase dual stimuli-responsive pesticide delivery system was constructed by combining mono-(6-amino-6-deoxy)-β-cyclodextrin (β-CD-NH2) with zeolitic imidazole skeleton-90 (ZIF-90) nanoparticles (IDC@ZIF-90-CD) loaded with indoxacarb. The average particle size of the prepared IDC@ZIF-90-CD was 249 nm, and the loading efficiency was 18.43%. The β-CD-NH2 coating on the surface of nanoparticles reduced the photodegradation of indoxacarb and prevented the premature release of the active ingredient. In vitro release kinetics showed that IDC@ZIF-90-CD rapidly released IDC under acidic and amylase conditions, consistent with the oral and intestinal environment of RIFAs. The results of bioactivity tests showed that IDC@ZIF-90-CD enhanced the toxicity of IDC toward RIFAs by increasing feeding and damaging intestinal cells. The mortality rate of the IDC@ZIF-90-CD-treated group was significantly higher than that of the IDC EC-treated group at 72 h. The nontargeted metabolomic results showed that IDC@ZIF-90-CD affected the metabolism of RIFAs by interfering with the metabolic pathways of six amino acids and one amino acid transport carrier, whereas IDC EC interfered with only two of these amino acid metabolic pathways. Overall, this work provides insight into the effective control of RIFA damage for sustainable pest management.
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