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MIL‐53(Fe)‐GO composite photocatalysts were successfully fabricated via a simple solid‐phase synthesis strategy, and they were applied as efficient visible‐light‐driven photocatalysts for the oxidation of organic dyes and the reduction of Cr(VI). The experimental results demonstrated that MIL‐53(Fe)‐GO composites exhibit enhanced photocatalytic activities compared with the pure MIL‐53(Fe) sample. Based on the photoelectrochemical analyses, the loading of GO could enhance visible‐light absorption and accelerate the separation and transfer of charge carries, leading to the improvement of photocatalytic performance. Moreover, more intimate interfacial contact and active sites in the system could be achieved via a simple solid‐phase synthesis strategy. They could also play important role in the enhancement of photocatalytic performance. Besides, a possible photocatalytic mechanism was also investigated in detail. [ABSTRACT FROM AUTHOR]

A honeycomb porous cadmium(II) metal–organic framework {[Cd(L)(H2O)] ⋅ NMP ⋅ 5H2O}n (1, H2L=1‐(4‐carboxyphenyl)‐1H‐pyrazole‐3‐carboxylic acid and NMP=1‐methyl‐2‐pyrrolidinone) was obtained using the solvothermal method. The luminescent molecules rhodamine B (RhB) and fluorescein (FL) were encapsulated in 1 using the immersion method to prepare RhB@1 and FL@1 dual emission composites. Additionally, a series of RhBx/FL1‐x@1 composites with varying luminescence properties were generated by altering the molar ratio of RhB to FL. Furthermore, the photoluminescence of RhB@1 and FL@1 was demonstrated to be caused by photoelectron transfer and fluorescence resonance energy transfer from 1 to the encapsulated guest module. Notably, RhB@1 showed the considerable improvement in fluorescence selectivity and detection limit (10−6 M) for metronidazole and dimetronidazole with remarkable recyclability. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes based on sulfate radical are considered one of the most promising wastewater treatment technologies currently. Among heterogeneous catalysts, cobalt metal–organic framework (MOF) has been widely reported. However, the inherent powder form of MOF hinders its practical application and reusability. Therefore, innovative methods to increase the loading capacity and the accessibility of MOF active sites in monolithic materials are required. Therefore, a simple and scalable method of fabricating a stable, hierarchical porous zeolitic imidazolate framework (ZIF‐67) 3D sponge by growing MOF on a short electrospun fiber network is shown. The sponge can efficiently activate peroxymonosulfate and rapidly degrade an exemplary organic dye (Rhodamine B) with a degradation efficiency of 100%. The resulting multilevel, hierarchical porous structure is beneficial to the mass transfer of reagents making the catalytic process efficient. This also enables the use of the ZIF‐67 as an efficient catalytic filter for continuous removal of dye. The sponge can be recycled and reused for several cycles due to its robustness without loss in efficiency. The proposed research strategy provides a new way to design MOF 3D monolithic materials. [ABSTRACT FROM AUTHOR]

Advanced oxidation process using reactive oxygen species (ROS) can be efficiently utilized to remove soluble contaminants from water. Herein, we have reported a facile method for the activation of molecular oxygen to produce ROS using Prussian blue analog (PBA)‐derived catalyst CoNx@NC. The two‐electron reduction of O2 by CoNx@NC produces H2O2, which is further dissociated into ⋅OH radicals and decomposes water‐soluble organic dye (methylene blue) and antibiotics (ciprofloxacin and amoxicillin). CoNx@NC is capable of removing 98 % of ciprofloxacin in a short period of time (65 minutes) in the presence of oxygen. Further, CoNx@NC can activate peroxodisulfate in the aqueous medium to produce ROS (SO4⋅−, and ⋅OH) and catalyzes the decomposition of the antibiotics and organic dye. The efficiency of the degradation of antibiotics and dye is improved when peroxodisulfate is used for the formation ROS. The higher oxidation potential and longer life‐time of SO4⋅− than ⋅OH improves the rate oxidation with peroxodisulfate. The Co−N coordination in CoNx@NC stabilizes the system against leaching and shows excellent stability for recycling (for five cycles) during the removal of contaminants. [ABSTRACT FROM AUTHOR]

BACKGROUND: Today, studies on the catalytic reduction of nitroarenes and dyes are of crucial because nitroarenes, especially 4‐nitrophenol (4‐NPh) and dyes, which are considered important pollutants in wastewater, can pose risks to humans. It is noteworthy that amines are known as valuable intermediates in many industries, therefore, providing an efficient method to achieve these compounds is necessary to protect the environment. In this project, a magnetic MOFs‐based catalyst (containing Cu species as an active site) was found to offer a unique and cost‐effective route for the catalytic reduction of nitroarene and organic dyes. RESULTS: In this study, a novel magnetic catalyst, Fe3O4@glu/Cu‐TAZ‐IMI, based on MOF was synthesized. The core‐shell structure of Fe3O4@glu, functionalized with aspartic acid with TAZ‐IMI and Cu(OAc)2, resulted in the formation of magnetic MOF structure. The structure of this new nanocomposite was identified by X‐ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Brunauer–Emmett–Teller (BET), Scanning electron microscopy/energy dispersive X‐ray (SEM/EDX), Thermogravimetric analysis (TGA), High‐resolution transmission electron microscopy (HRTEM), Value stream mapping (VSM), Raman spectroscopy and Inductively coupled plasma‐optical emission spectrometry (ICP‐OES). The catalytic performance of the synthesized catalyst was evaluated for the reduction of nitro compounds and organic dyes, and the results were validated by Gas chromatography‐mass (GC–MS) and ultraviolet light (UV–Vis) spectroscopy. Moreover, the rate constants for the reduction of 4‐NPh, Congo red (CR), and Methylene blue (MB) followed pseudo first‐order kinetics model, which calculated values of 0.31 min−1, 0.355 min−1 and 0.044 s−1, respectively. CONCLUSION: The catalytic efficacy of Fe3O4@glu/Cu‐TAZ‐IMI catalyst remained intact during the reduction of nitroarenes and organic dyes in aqueous and mild conditions. The findings demonstrate that this novel heterogeneous mesoporous catalyst exhibits exceptional catalytic activity and remarkable stability towards reduction reactions. Moreover, owning to its thermal and structural stability, the catalyst could be easily magnetically separated, recovered, and reused for up to 10 consecutive cycles without experiencing significant activity decline, effectively preventing the depletion of copper species from its structure. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Dye is an organic substance that seriously threatens the water environment. Using a solvothermal technique, MIL‐100(Fe) and M‐Fe have been synthesized to effectively remove methylene blue (MB) and methyl orange dyes from wastewater. The microstructures of the two products were analyzed using scanning electron microscopy, Fourier transform infrared, Brunauer–Emmett–Teller (BET), thermogravimetric (TG), and X‐ray diffractometer (XPS) test. Optimized the optimal experimental parameters through batch processing experiments, when the pH was 5 and 2, the amount of adsorbent was 50 mg, the temperature was 25°C, and the dye concentration was 30 mg/L, MIL‐100(Fe) and M‐Fe had the highest removal rates of MB, at 98.95% and 94.11%, respectively. Adsorption process was well described by the Freundlich isotherm and pseudo‐second‐order kinetics. After three regeneration experiments, the removal rate was still high. The removal efficiencies of the two adsorbents for MB were similar. However, the regeneration performance of M‐Fe was better. Through the simulation of materials studio, the adsorption energy of the product and MB is −0.93 eV, which is favorable for adsorption. The results show that the two adsorbents can effectively remove MB from wastewater and have broad application prospects. [ABSTRACT FROM AUTHOR]

In this study, a novel hydroxyapatite (HAp)‐based composite, Co‐Cu/ZIF@HAp, was constructed through in situ growth and simultaneous sonication followed by magnetic string. Herein, the HAp‐based nanocomposite was obtained in which HAp was coated with cobalt–copper bimetallic zeolitic imidazolate framework (ZIF) in one‐pot synthesis method. The as‐synthesized composite was characterized by PXRD, FTIR, FE‐SEM, EDS, HR‐TEM, TGA‐DTG, XPS, BET, and UV‐DRS techniques, which suggested that HAp was well coated with bimetallic ZIF. The prepared composite was utilized as a catalyst in degradation of organic pollutants. Removal of organic pollutants such as organic dyes has become indispensable due to their higher stability, toxicity, and mutagenic nature. Two commonly found organic dyes, namely, Eosin Yellow (EY) and Brilliant Green (BG), were chosen for the investigation of photocatalytic activity of the as‐prepared catalyst. The degradation process was carried out under solar radiation, and there was no utilization of any oxidizing and reducing agent. Several parameters such as amount of catalyst dose, initial concentration of the dye solution, and effect of different pH conditions were evaluated for better understanding of photocatalytic performance of Co‐Cu/ZIF@HAp composite. Both EY and BG dyes were almost degraded up to 98.3% and 99.5%, respectively, within 50 min by the as‐prepared nanocomposite. Also, quenching test was performed that confirmed the formation of superoxide radicals (O2−.) as reactive oxygen species (ROS) in the photodegradation process. The as‐synthesized catalyst was repeatedly used for five times to ascertain the stability and reusability of catalyst. [ABSTRACT FROM AUTHOR]

Environmental contamination due to organic pollutants including organic dyes (e. g. methylene blue (MB)) and paraquat (i. e. methyl viologen (MV)) has become a serious problem. Herein, the removal for toxic cations of methylene blue (MB+) and methyl viologen (MV2+) has been realized by a three‐dimensional (3D) anionic microporous metal‐organic framework, namely [Me2NH2][In(TDC)2] ⋅ 1.5DMA ⋅ H2O (FJSM‐InMOF). FJSM‐InMOF is capable of selectively adsorbing MB+ in the presence of various dyes due to the effects of size‐exclusion and charge‐matching. Particularly, the strategy of combining adsorption and photocatalytic degradation realizes the thorough treatment of MB+, which has been rarely reported. The adsorbent material can be easily regenerated and reused. Moreover, FJSM‐InMOF exhibits a high capacity and rapid kinetics towards more toxic MV2+. This work poses a new way for the selective removal of cationic organic pollutants and highlights the significance of combining different methods for the decontamination of organic pollutants. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) had been widely used in adsorption, but nanoscale MOFs always caused secondary pollution which attributed to the difficultly of removing from water completely. To solve the problem, nanoscale metal‐organic framework MIL‐53(Fe) was uniformly grown onto carbon nanotubes (CNTs)/ethylene vinyl acetate (EVA) fiber to obtain MIL‐53(Fe)/CE fiber, and the loading content of MIL‐53(Fe) reached to 60.6 wt %. The MIL‐53(Fe)/CE fiber exhibited excellent adsorption capacity for congo red (CR) and medium orange 1 (MO1), which the removal was 99.4 % and 96.8 %. In addition, the composite could release nearly all adsorbed dyes after 1 h, which had the potential of recycling. The adsorption content of pure MIL‐53(Fe) for MO1 was about 68.4 % after 4 cycles, and the composite reached to 82.4 % after 9 cycles, implying the desirable reusability of composite. The MIL‐53(Fe)/CE fiber displayed potential application prospects in dye adsorption because of its ideal separation property, fast dye releasing and good recyclability. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs), bridging metal‐containing second building units by organic ligands, have provided a versatile platform for the design of heterogeneous catalysis. In the last decade, various photo‐responsible MOFs have been designed and prepared, exhibiting outperformed catalytic performance. Among them, MOFs featuring organic photosensitizers for photoinduced organic transformations remain less investigated, due probably to the large steric demands and low symmetry of typical organic dyes. In view of the promising potential of integrating versatile MOFs with organic photosensitizers, this Concept summarizes recent advances in this research area. [ABSTRACT FROM AUTHOR]

Two Co(II) coordination polymers, {[Co(ca)(bpe)(H2O)] ⋅ H2O}n (1) and [Co(ca)(bibp)]n (2) (H2ca=citraconic acid, bpe=1,2‐di(4‐pyridyl)ethylene, bibp=4,4′‐bis(imidazolyl)biphenyl) were prepared by hydrothermal reactions, and characterized by single‐crystal X‐ray diffractions, elemental analysis, FT‐IR, PXRD and TGA. Compound 1 shows a 2D grid layer containing Co‐carboxylate chains. Compound 2 exhibits a three‐dimensional metal‐organic framework with the dia topology type and 66 topology symbol. Both compounds have high thermal stabilities and good phase purity. The photocatalytic reactions of two compounds were investigated under UV irradiation in the presence of H2O2, and the results show that both compounds are highly efficient photocatalysts for MB and RhB degradation, which may be used as potential materials for wastewater treatment. [ABSTRACT FROM AUTHOR]

The combination of high crystallinity and rich host‐guest chemistry in metal‐organic frameworks (MOFs), have situated them in an advantageous position, with respect to traditional porous materials, to gain insight on specific weak noncovalent supramolecular interactions. In particular, sulfur σ‐hole interactions are known to play a key role in the biological activity of living beings as well as on relevant molecular recognitions processes. However, so far, they have been barely explored. Here, we describe both how the combination of the intrinsic features of MOFs, especially the possibility of using single‐crystal X‐ray crystallography (SCXRD), can be an extremely valuable tool to gain insight on sulfur σ‐hole interactions, and how their rational exploitation can be enormously useful in the efficient removal of harmful organic molecules from aquatic ecosystems. Thus, we have used a MOF, prepared from the amino acid L‐methionine and possessing channels decorated with −CH2CH2SCH3 thioalkyl chains, to remove a family of organic dyes at very low concentrations (10 ppm) from water. This MOF is able to efficiently capture the four dyes in a very fast manner, reaching within five minutes nearly the maximum removal. Remarkably, the crystal structure of the different organic dyes within MOFs channels could be determined by SCXRD. This has enabled us to directly visualize the important role sulfur σ‐hole interactions play on the removal of organic dyes from aqueous solutions, representing one of the first studies on the rational exploitation of σ‐hole interactions for water remediation. [ABSTRACT FROM AUTHOR]

In this work, highly effective and rapid removal of cationic carcinogenic organic dye molecules is achieved through the implementation of a novel anionic metal–organic framework (MOF). Benefit from reticular chemistry, an anionic pts topology‐directed MOF [CH3NH3][In (TPTAB)4]·solvents (In‐TPTAB, H4TPTAB = [1,1′:3′,1″‐terphenyl]‐4,4′,4″,6′‐tetracarboxylic acid) has been solvothermally synthesized. The structural characteristics of high porosity and the large size 1D channel modified by uncoordinated O sites promote In‐TPTAB to be a promising adsorbent material. By ion exchange, In/Cu‐TPTAB exhibits obviously increased BET surface area (248 m2 g−1) compared with In‐TPTAB (55 m2 g−1). More importantly, In‐TPTAB presents commendable performances with the maximum adsorption capacities for toxic dye BR9 and MLB are up to 368 and 304 mg g−1, and the adsorption rates are 10.9 and 6.7 mg g−1 min−1, respectively. It is noteworthy that the high‐efficiency capacity of In‐TPTAB in capturing dyes surpasses many reported adsorbent materials. The mechanism of physical adsorption can be ascribed to the synergistic effect of multiple host‐guest interactions. Coupled with the good recyclable, push In‐TPTAB to be potential used for the removal of cationic organic pollutants [ABSTRACT FROM AUTHOR]

We demonstrate enhanced dye adsorption capacity of nanoclay by decoration with chromium‐based MOF (MIL‐101) nanostructure. The Clay/Cr‐MOF composite exhibits a crystalline structure with high thermal stability. Moreover, it shows the superior specific surface area (4959 m2/g) and porosity which is beneficial for wastewater treatment. The developed Clay‐MOF composite exhibits superb adsorption capacity toward various organic dyes as compared with existing materials. The adsorption experiments revealed high adsorption capacity and selective dye removal efficiency of MOF‐modified nanoclay with reusability for multiple regeneration cycles. The adsorption kinetics was found to obey the pseudo‐second‐order kinetic model. These findings provide new insights into the application of such porous adsorbents for wastewater treatment applications. [ABSTRACT FROM AUTHOR]

Polymorphism control of metal‐organic frameworks is highly desired for elucidating structure‐property relationships, but remains an empirical process and is usually done in a trial‐and‐error approach. We adopted the rarely used actinide cation Th4+ and a ditopic linker to construct a series of thorium‐organic frameworks (TOFs) with a range of polymorphs. The extraordinary coordination versatility of Th4+ cations and clusters, coupled with synthetic modulation, gives five distinct phases, wherein the highest degree of interpenetration (threefold) and porosity (75.9 %) of TOFs have been achieved. Notably, the O atom on the capping site of the nine‐coordinated Th4+ cation can function as a bridging unit to interconnect neighboring secondary building units (SBUs), affording topologies that are undocumented for other tetravalent‐metal‐containing MOFs. Furthermore, for the first time HCOOH has been demonstrated as a bridging unit of SBUs to further induce structural complexity. The resulting TOFs exhibit considerably different adsorption behaviors toward organic dyes, thus suggesting that TOFs represent an exceptional and promising platform for structure‐property relationship study. [ABSTRACT FROM AUTHOR]

Phosphor‐converted white light‐emitting diodes (pc‐WLEDs), as a main approach of solid‐state white light illumination, have caught tremendous attention and achieved enormous progress in the past decades. Since the phosphor plays a dominating role in the final property of pc‐WLEDs, the exploration for high‐performance phosphor has become a challenging and targeted research topic. In this regard, metal–organic frameworks (MOFs) are emerging to offer a fascinating platform for well color‐tuning flexibility and designability endowed by their diversified architectures, devisable pore structures and affluent luminescent centers. In this review, the design strategies of achieving high‐performance phosphor with the doping of luminescent lanthanide ions, organic ligands, and diverse luminescent guest species including organic dyes, metal complexes, quantum dots in MOF matrix are highlighted, and the representative advances in the development of MOF phosphor are presented, providing guidance and reference for further research of phosphor for pc‐WLEDs. [ABSTRACT FROM AUTHOR]

A novel porous metal–organic framework Cu‐BCPPy based on a desymmetrized heterofunctional ligand 3,5‐di(4‐carboxyphenyl)pyridine has been successfully synthesized under solvothermal conditions. The framework possesses two sizes of 2D straight channels, which are constructed by one pair and three pairs of helixes, respectively. The distortion of the ligand leads to the structure exhibiting a new type of (3,6)‐connected topology. According to the structural characteristic, Cu‐BCPPy can effectively adsorb large carcinogenic organic dyes sudan III (SD III) and direct black 38 (DB 38) but exclude small molecular dyes. Hence, Cu‐BCPPy exhibits effective and selective adsorption performance for the carcinogenic dye DB 38 on the equal proportional mixture dyes methyl orange (MO) and DB 38, fluorescein and DB 38, and basic red 2 (BR 2) and DB 38 with different sizes. In addition, Cu‐BCPPy can be also provided with the characteristic of high iodine adsorption and release, which indicates that it is a promising candidate material for selectively adsorption and separation of many substances. [ABSTRACT FROM AUTHOR]

A series of binary composite photo‐catalyst BiOBr/MgBTC (the ligand of MgBTC is 1, 3, 5‐benzenetricarboxylate = H3BTC) with different content of BiOBr have been designed and used to degrade the traditional dye rhodamine B (RhB). As‐prepared binary composites have been first obtained via a simple hydrothermal system and subsequently deposited onto the BiOBr substrates. The composites exhibited better catalytic performance compared with the pristine BiOBr, and the performance of BM‐55 (synthesized by 0.55 mmol BiOBr and 0.45 mmol MgCl2•6H2O) was the most efficient and its removal rate of RhB can reach 98.3% within 60 min. The composite photo catalyst was characterized by X‐ray diffraction (XRD), infrared (IR), scanning electron microscope (SEM), X‐ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and electrochemical impedance spectroscopy (EIS), respectively. In the free radical trapping experiments, it can be seen that the main photo‐catalytic active species are superoxide radicals (•O2−) and holes (h+). This work can provide considerable opportunities to the development of various metal–organic frameworks (MOF)‐based visible light photo‐catalysts and modified 2D bismuth ox halide materials (BiOX) for use in environmental cleaning application. [ABSTRACT FROM AUTHOR]

Metals Organic Frameworks (MOFs) are promising crystalline, embrittled materials generally produced in powdering form with varied remarkably functionalities. In contrary, polymers are flexible and processable materials. Therefore, obtaining shaped solids gathering polymer malleability and MOFs properties such as their photocatalytic activities, have attracted many researchers' attention. This work, reports the successful fruitful incorporation of two different Fe‐based MOFs into a polymer matrix via a facile and cheap photopolymerization process upon mild visible light irradiation at 405 nm. The as‐prepared photocomposites display excellent stability and photocatalytic performance for several Acid Black degradation cycles. Hence, approximatively, 95 % of this model dye is decomposed by the two MIL‐100(Fe)/polymer and MIL‐88 A(Fe)/polymer composites under just 30 min of UV‐Visible lamp irradiation. Incorporation of the MOFs into the polymer is confirmed by several techniques including Scanning Electron Microscopy (SEM), Energy‐Dispersive X‐ray analysis (EDX), Transmission Electron Microscopy (TEM), X‐ Ray Diffraction analysis (DRX), Fourier‐Transform Infrared Spectroscopy (FTIR). Furthermore, these photocatalysts exhibit a high thermal stability, excellent rigidity and low band gap energy characterized by Thermogravimetric Analysis (TGA), Atomic Force Microscopy (AFM), Dynamic Mechanical Analysis (DMA) and UV‐Visible diffuse reflectance spectroscopy, respectively. [ABSTRACT FROM AUTHOR]

By using tritopic and ditopic organic linkers derived from the same 2,4,6‐triphenylpyridine core, copper(II) metal‐organic frameworks with different three‐dimensional structures have been successfully synthesized under ambient conditions. The crystalline framework, PTBMOF ([Cu3(PTB)2(H2O)3]n, where H3PTB=4,4′,4′′‐(pyridine‐2,4,6‐triyl)tribenzoic acid, was observed to be mesoporous in nature and exhibited dual functionality in the removal of organic dyes. While cationic dyes such as methylene blue and malachite green, which are of different sizes, were adsorbed by PTBMOF; anionic dyes such as tartrazine could be effectively degraded in a photo‐Fenton‐like reaction catalyzed by the MOFs under irradiation with visible light. [ABSTRACT FROM AUTHOR]

In this study, a novel mixed‐matrix membrane (MMM) based on covalent incorporation of poly(styrene‐alt‐maleic anhydride) (PSMA) with a metal‐organic framework (MOF) UiO‐66‐NH2 was prepared and utilized for dye removal from aqueous solution. The fabrication of PSMA and UiO‐66‐NH2 was carried out by the amidation reaction between the maleic anhydride ring and amino functional group affording crosslinked MOF/PSMA membrane. The separate UiO‐66‐NH2 and PSMA solutions were mixed before cast films were produced. The MMM was prepared with final UiO‐66‐NH2 wt % content from 0 to 30 % in each membrane. The formation of MMM was confirmed with FT‐IR, PXRD, TGA, SEM, and XPS analysis. The MMM having high adsorption capacity was used for the separation of methylene blue (MB) and methyl orange (MO) as organic dye pollutants commonly found in wastewater. The MMM could be recycled and still maintained 75 and 52 % retention of MB and MO on the third reuse cycle, respectively. The results suggest that the MOF incorporated PSMA was an outstanding membrane for the development of filtration techniques for decontamination of water resources. [ABSTRACT FROM AUTHOR]

A new uranyl containing metal–organic framework, RPL‐1: [(UO2)2(C28H18O8)]. H2O (RPL for Radiochemical Processing Laboratory), was prepared, structurally characterized, and the solid‐state photoluminescence properties explored. Single crystal X‐ray diffraction data reveals the structure of RPL‐1 consists of two crystallographically unique three dimensional, interpenetrating nets with a 4,3‐connected tbo topology. Each net contains large pores with an average width of 22.8 Å and is formed from monomeric, hexagonal bipyramidal uranyl nodes that are linked via 1,2,4,5‐tetrakis(4‐carboxyphenyl)benzene (TCPB) ligands. The thermal and photophysical properties of RPL‐1 were investigated using thermogravimetric analysis and absorbance, fluorescence, and lifetime spectroscopies. The material displays excellent thermal stability and temperature dependent uranyl and TCPB luminescence. The framework is stable in aqueous media and due to the large void space (constituting 76 % of the unit cell by volume) can sequester organic dyes, the uptake of which induces a visible change to the color of the material. [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of Cr (VI) is investigated over phosphonate‐based metal–organic frameworks (MOFs) structured as STA‐12(M)(M = Mn, Fe, Co, Ni). The removal of Cr (VI) appears to be faster with STA‐12(Fe) under natural sunlight. The correlation among responses to effective variables as main and interactions were optimized by central composite design (CCD) in response surface methodology (RSM). Moreover, STA‐12(Fe) has exhibited considerable synergistic photocatalytic activity for dyes (MO and RhB) degradation and Cr (VI) reduction. The reduction ratio of Cr (VI) was increased extremely after addition of MO or RhB. The highest photocatalytic activity of dyes degradation and Cr (VI) reduction appeared under the dye/Cr (VI) weight ratio of 3:1. To determine the most important species that affected the photocatalytic reduction, trapping experiments were carried out, using various kinds of scavenger species. Finally, a probable reaction mechanism has been investigated in detail. [ABSTRACT FROM AUTHOR]

A novel PTA/ZIF‐8@CA composite material (PTA = phosphotungstic acid; CA = cellulose aerogel) with multilayer three‐dimensional network structure was synthesized with cellulose aerogel as the framework and MOFs as the filler. The results showed that the degradation rates of methylene blue at δ = 10 ppm reached 99.8 % respectively in 30 min under the conditions of PTA/ZIF‐8@CA input amount of 0.6 g·L–1 and pH = 5. The degradation rate of rhodamine B at δ = 10 ppm reached 99.7 % in 60 min. This shows that PTA/ZIF‐8@CA has excellent degradation efficiency and short‐term performance. In addition, after 5 photocatalytic cycles, the degradation rates of methylene blue and rhodamine B by PTA/ZIF‐8@CA were still 83.0 % and 82.5 %, respectively, reflecting that PTA/ZIF‐8@CA has terrific photocatalysis stability. [ABSTRACT FROM AUTHOR]

A series of Pt modified TiO2–x/C composites with higher specific surface area were obtained by using a Zn‐Ti heterometallic metal‐organic framework (MOF) as the precursor. The photocatalytic activities of these composites were studied by methylene blue (MB) as a representative organic pollutant. The chemical composition and porosity of these composites can be adjusted by changing the pyrolysis temperature. Among them, the sample being pyrolyzed at 1000 °C (PTC‐P10) showed excellent photocatalytic performance, and its rate constant of degradation of MB was higher than that of ATC‐P10 (Ag modified TiO2–x/C composites) due to the rapid capture of electrons and the expansion of the photoresponse range caused by Pt modifying. This work represents a novel approach towards Pt modified TiO2–x/C composites as photocatalysts. [ABSTRACT FROM AUTHOR]

An optimized structure is of considerable importance for nickle oxide (NiO)‐based materials to achieve high performance as catalyst for contaminant degradation due to the inherent large band gap. Herein, a series of hybrids of NiO nanoparticles doped with zinc oxide (ZnO) semiconductor were fabricated via a facile one‐step calcination of bimetallic metal‐organic frameworks with varied Ni2+/Zn2+ molar ratios (MOF‐NiZn). It is worth noting that partial positions of Ni in NiO lattice are replaced by Zn to form a Ni0.9Zn0.1O phase. Benefiting from the unique hybrid advantage, the rationally designed material could effectively lower the band gap of NiO, thus improving the photocatalytic performance. The optimized ZnO/Ni0.9Zn0.1O‐82 catalyst exhibits the highest degradation activity towards methylene blue (MB) with efficiency up to 97.4 % within 60 min. Additionally, the radicals trapping experiments reveal that the photo‐generated hydroxyl radical (.OH) is the predominant active species during the photodegradation of MB. [ABSTRACT FROM AUTHOR]

A series of dye@MOF composites were synthesized through in situ encapsulation of luminous rhodamine B (RhB) molecules into a blue‐emissive zirconium–naphthalene‐based metal–organic framework (Zr‐MOF). The fabricated RhB@Zr‐MOF composites exhibit tunable dual‐emissive characteristics due to the process of resonant energy transfer from Zr‐MOF to RhB. Notably, one of the RhB@Zr‐MOF composites (R@D3) exhibited a weak emission at 420 nm and a strong emission at 607 nm, for which the two emissions possess large distinctions in location and intensity and can be referenced with each other in sensing analytes. By using relative fluorescence intensity instead of their absolute fluorescence intensity as the detection signals, R@D3 served as a built‐in self‐calibrated platform to selectively detect Fe3+ and Cr2O72− ions in water. Compared with the pristine Zr‐MOF, the R@D3 composite shows enhanced sensing selectivity to Fe3+ and higher sensibility to Cr2O72−. This study displays the advantages of combining organic dyes with robust Zr‐MOFs in tuning fluorescence and sensing performance. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have attracted much interest in the fields of gas separation and storage, catalysis synthesis, nonlinear optics, sensors, luminescence, magnetism, photocatalysis gradation and crystal engineering because of their diverse properties and intriguing topologies. A Cu–MOF, namely poly[[(μ2‐succinato‐κ2O:O′){μ2‐tris[4‐(1,2,4‐triazol‐1‐yl)phenyl]amine‐κ2N:N′}copper(II)] dihydrate], {[Cu(C4H4O4)(C24H18N10)]·2H2O}n or {[Cu(suc)(ttpa)]·2H2O}n, (I), was synthesized by the hydrothermal method using tris[4‐(1,2,4‐triazol‐1‐yl)phenyl]amine (ttpa) and succinate (suc2−), and characterized by IR, powder X‐ray diffraction (PXRD), luminescence, optical band gap and valence band X‐ray photoelectron spectroscopy (VB XPS). Cu–MOF (I) shows a twofold interpenetrating 4‐coordinated three‐dimensional CdSO4 topology with point symbol {65·8}. It presents good photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) under visible‐light irradiation. A photocatalytic mechanism was proposed and confirmed. [ABSTRACT FROM AUTHOR]

An anionic multifunctional porous metal organic framework (MOF), [Cu2THBA(H2O)2]·(C3H7NO)12·(H2O)10 (1) (H4THBA = p‐terphenyl‐3,2′′,3′′,5,5′′,5′′′‐ hexcarboxylic acid) with NbO‐type topology was synthesized and characterized. Due to multiple functional sites and suitable pore size, the desolvated compound 1a exhibits high separation selectivity for C2H2/CO2 of 30 and C2H2/CH4 of 131 at 1 kPa at room temperature. Compound 1 can also efficiently and completely separate methylene blue (MB+) molecules of low concentrations from aqueous solution in 12 h. [ABSTRACT FROM AUTHOR]

Two novel POM‐based metal‐organic frameworks, [Ag7(L1)2·(µ2‐OH)4][H3VW12O40] (1) and [Ag8(L2)4][VW12O40]·4H2O (2) have been isolated by altering the isomeric organic ligands {5‐[n‐(1,2,4‐triazol‐4‐yl)phenyl]‐1H‐tetrazole: n = 3 (HL1); n = 4 (HL2)} under hydrothermal conditions. Due to L1 acts as a V‐shaped linker, compound 1 displays a 3D MOF with three types of metallocycles, in which the Keggin polyanions locat in the largest metallocycle (the size of void ca. 13.31 Å × 13.53 Å). However, when the ligand is replaced by straight ligand L2, compound 2 with a different structure is obtained. Although compound 2 is also a 3D MOF, the types of metallocycle are reduced to one. The Keggin polyanions are seated in the only metallocycle (the size of void ca. 13.6 Å × 13.7 Å). In addition, the adsorption behaviors of the title compounds for organic dyes were investigated in detail. In particular, compound 1 could selectively separate MB+ from the mixture of MB+/RhB+ and MB+/MO– within 5 min, which can be used as a chromatography column for dyes removal. Two new metallocycle‐supported POM‐based metal‐organic frameworks were isolated by employing isomeric N‐riched rigid organic ligands (straight and the V‐shaped). It is Interesting that both modes can form metallocycles with Ag+ cations and further to incorporate POMs. Obtained compounds could fast and selectively separate MB+ dye molecules from the mixtures of MB+/RhB+ and MB+/MO– for a moment, respectively. [ABSTRACT FROM AUTHOR]

The presence of residual organic dyes in water resources or wastewater treatment systems, derived mainly from effluents of different industries, is a major environmental problem with no easy solution. Herein, an ecofriendly, water‐stable metal–organic framework was prepared from a derivative of the natural amino acid l‐serine. Its functional channels are densely decorated with highly flexible l‐serine residues bearing hydroxyl groups. The presence of such a flexible and functional environment within the confined environment of the MOF leads to efficient removal of different organic dyes from water: Pyronin Y, Auramine O, Methylene Blue and Brilliant Green, as unveiled by unprecedented snapshots offered by single‐crystal X‐ray diffraction. This MOF enables highly efficient water remediation by capturing more than 90 % of dye content, even at very low concentrations such as 10 ppm, which is similar to those usually found in industrial wastewaters. Remarkably, the removal efficiency is improved in simulated contaminated mineral water with multiple dyes. Multidye capture: A highly crystalline metal–organic framework, derived from the amino acid l‐serine, captures efficiently different organic dyes at very low concentration, even in the presence of multiple dyes (see figure). In addition, single‐crystal X‐ray diffraction offered unprecedented snapshots of the dye‐capture process. [ABSTRACT FROM AUTHOR]

Photoactive metal-organic frameworks (MOFs) have lately emerged as a class of crystalline porous materials, which provides an advanced platform to develop catalysts for the photocatalytic decolorization of wastewater. Controllable integration of pure MOFs into other active materials creates fabrication protocols for new multifunctional hybrids with superior photocatalytic properties for dye degradation into individual components, and the calcination of transition-metal MOF precursors affords a convenient and practical route for preparation of nanosized photocatalysts with novel structures and good purity. Although the application of pure MOFs for organic pollutant decomposition has been reviewed previously, there have been significant advances in diverse MOF-based composites and their derivatives for dye degradation, which have rarely been reviewed. This review aims to fill this gap and discuss the various influencing factors, the reaction kinetics, and mechanisms of dye degradation, considering the period from 2014 to 2016. Finally, the challenges and outlooks for dye decomposition by MOF-based materials are suggested. [ABSTRACT FROM AUTHOR]

The design of artificial systems that mimic highly evolved and finely tuned natural enzymes is a promising subject of intensive research. The assembly of O-symmetric cubic structures with an Fe8L6 formula was reported through the direct combination of a C4-symmetric tetraphenylethylene-based ligand with a C3-symmetric tris(bipyridine)iron node. The robust metal-organic cubes are rich in π-electron density and provide favorable interactions with planar polycyclic aromatic hydrocarbons. Within the confined space of the host, the aromatic hydrocarbons molecules are forced closer to the redox active host, and the photoinduced electron transfer (PET) is modified into a pseudo-intramolecular pathway. These iron vertices within the cubes exhibit suitable redox potential for electrochemical reduction of protons and the well-modified PET is further tailored to create artificial systems for light-driven hydrogen evolution from water through the encapsulation of fluorescein dyes. Control experiments based on a mononuclear compound resembling the iron corner of the octahedron suggest an enzymatic dynamic behavior. The new, well-elucidated reaction pathways and the increased molarity of the reaction within the confined space render these supramolecular systems superior to other relevant systems. [ABSTRACT FROM AUTHOR]

Ionic metal-organic frameworks (MOFs) are a subclass of porous materials that have the ability to incorporate different charged species in confined nanospace by ion-exchange. To date, however, very few examples combining mesoporosity and water stability have been realized in ionic MOF chemistry. Herein, we report the rational design and synthesis of a water-stable anionic mesoporous MOF based on uranium and featuring tbo-type topology. The resulting tbo MOF exhibits exceptionally large open cavities (3.9 nm) exceeding those of all known anionic MOFs. By supercritical CO2 activation, a record-high Brunauer-Emmett-Teller (BET) surface area (2100 m2 g−1) for actinide-based MOFs has been obtained. Most importantly, however, this new uranium-based MOF is water-stable and able to absorb positively charged ions selectively over negatively charged ones, enabling the efficient separation of organic dyes and biomolecules. [ABSTRACT FROM AUTHOR]

Cationic frameworks can selectively trap anions through ion exchange, and have applications in ion chromatography and drug delivery. However, cationic frameworks are much rarer than anionic or neutral ones. Herein, we propose a concept, preemptive coordination (PC), for targeting positively charged metal-organic frameworks (P-MOFs). PC refers to proactive blocking of metal coordination sites to preclude their occupation by neutralizing ligands such as OH−. We use 20 MOFs to show that this PC concept is an effective approach for developing P-MOFs whose high stability, porosity, and anion-exchange capability allow immobilization of anionic nucleotides and coenzymes, in addition to charge- and size-selective capture or separation of organic dyes. The CO2 and C2H2 uptake capacity of 117.9 cm3 g−1 and 148.5 cm3 g−1, respectively, at 273 K and 1 atm, is exceptionally high among cationic framework materials. [ABSTRACT FROM AUTHOR]

A strategy by encapsulating organic dyes into the pores of a luminescent metal-organic framework (MOF) is developed to achieve white-light-emitting phosphor. Both the red-light emitting dye 4-( p-dimethylaminostyryl)-1-methylpyridinium ( DSM) and the green-light emitting dye acriflavine ( AF) are encapsulated into a blue-emitting anionic MOF ZJU-28 through an ion-exchange process to yield the MOF⊃dye composite ZJU-28⊃DSM/AF. The emission color of the obtained composite can be easily modulated by simply adjusting the amount and component of dyes. With careful adjustment of the relative concentration of the dyes DSM and AF, the resulting ZJU-28⊃DSM/AF (0.02 wt% DSM, 0.06 wt% AF) exhibits a broadband white emission with ideal CIE coordinates of (0.34, 0.32), high color-rendering index value of 91, and moderate correlated color temperature value of 5327 K. Such a strategy can be easily expanded to other luminescent MOFs and dyes, thus opening a new perspective for the development of white light emitting materials. [ABSTRACT FROM AUTHOR]

Cover Feature: Rational Design of a Uranyl Metal-Organic Framework for the Capture and Colorimetric Detection of Organic Dyes (Chem. Eur. J. 61/2020) Keywords: actinide; adsorption; luminescence; metal-organic frameworks; uranium EN actinide adsorption luminescence metal-organic frameworks uranium 13744 13744 1 11/06/20 20201102 NES 201102 B A new uranyl containing metal-organic framework b was prepared and the diffraction data reveals the structure consists of interpenetrating 3D nets with a 4,3-connected tbo topology. Actinide, adsorption, luminescence, metal-organic frameworks, uranium. [Extracted from the article]

phosphonate‐based bimetallic metal‐ organic frameworks, namely STA‐12(M1, M2) (M1, M2 = Mn, Fe, Co), show photocatalytic activity for the degradation of Rhodamine B (RhB) and Methylene blue (MB) from aqueous solution under natural sunlight irradiation. The degradation of the dyes, appears to be faster with STA‐12(Fe, Mn) than other synthesized MOFs. Thus, photo‐Fenton oxidative discoloration of dyes has been studied by H2O2 catalyzed with the STA‐12(Fe, Mn). The process is first order with respect to dyes and the synergistic index in the STA‐12(Fe, Mn)/sunlight/H2O2system reached as high as 472%. Mineralization of dyes was discussed by spectroscopic and TOC measurement. Besides, the efficiency of STA‐12(Fe, Mn) used in photocatalytic process was attentively investigated through the characterization of reactive radicals, the stability and reusability of the photocatalyst, also the effect of operational parameters such as H2O2 dosage, solution pH and initial dye concentration. This work demonstrates the first example of facilitating photo‐Fenton‐like excitation of H2O2 via phosphonate based mixed metal organic frameworks as photocatalysts and explained a new opportunity for solar‐induced AOP environmental remediation and protection. [ABSTRACT FROM AUTHOR]

A novel eco‐friendly water‐stable metal–organic framework, prepared from a derivative of the natural amino acid L‐serine and featuring functional channels, efficiently captures different organic dyes at very low concentrations, similar to those observed in industrial discharges. In addition, single‐crystal X‐ray diffraction offers unprecedented snapshots of the host–guest interactions governing the capture processes. More information can be found in the Full Paper by J. Ferrando‐Soria, D. Armentano, E. Pardo, et al. on page 17712. [ABSTRACT FROM AUTHOR]

A strategy of encapsulation of organic dyes into the pores of a luminescent metal–organic framework (MOF) to achieve a white‐light‐emitting phosphor has been developed by G. Qian and co‐workers on page 4796. The resultant MOF ⊃ dye composite exhibits a broadband white emission with ideal CIE coordinates of (0.34, 0.32), high CRI value of 91, and moderate CCT value of 5327 K. [ABSTRACT FROM AUTHOR]