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[Display omitted] • Rare [Cu 4 I 2 ]2+ cationic cluster constructs a novel 3D Cu(I)-MOF. • The stable Cu(I)-MOF shows sensitive detection ability for ROX, NFZ and NFT. • Hierarchical porous Cu(I)-MOF/MF composites were built by a one-pot method. • The Cu(I)-MOF/MF exhibits remarkable adsorption capacity towards ROX, NFZ and NFT. Fluorescence quenching induced by photoinduced electron transfer (PET) stands as an effective strategy for identifying water pollutants. Herein, a novel (4, 8)-connected three-dimensional framework Cu(I)-MOF ([Cu 2 I(tpt)] n) with unique 8-connected [Cu 4 I 2 ]2+ cationic clusters is designed by employing the nitrogen-rich ligand (Htpt = 5-[4(1 H -1,2,4-triazol-1-yl)]phenyl-2 H -tetrazole). Water-stabilized Cu(I)-MOF exhibits outstanding fluorescence properties, facilitating its application in detecting organic pollutants in water. Benefiting from the fact that the Cu(I)-MOF possesses a higher lowest unoccupied molecular orbitals (LUMO) energy level than that of the analyte, the rapid d-PET can occur, entitling Cu(I)-MOF to a sensitive fluorescence quenching response to roxarsone (ROX), nitrofurazone (NFZ) and nitrofurantoin (NFT) (with detection limits as low as 0.13 µM, 0.15 µM, and 0.13 µM, respectively). The nitrogen-containing sites of melamine foam (MF) are utilized to facilitate the anchoring and growth of Cu-MOF crystals, which enables the preparation of hierarchical microporous − macroporous Cu(I)-MOF/MF composites. The ordered porous structure of Cu(I)-MOF/MF provides cavities and open sites for the efficient removal of ROX (q max = 210.6 mg∙g−1), NFZ (q max = 111.5 mg∙g−1) and NFT (q max = 238.9 mg∙g−1) from water. This characteristic endows the Cu(I)-MOF/MF with rapid and recyclable adsorption capacity. Therefore, this work provides valuable insights to address the problem of detection and removal of pollutants in the aquatic environment. [ABSTRACT FROM AUTHOR]

[Display omitted] As a noble metal with extremely high economic benefits, the recovery of silver ions has attracted a particular deal of attention. However, it is a challenge to recover silver ions efficiently and selectively from aqueous solutions. In this research, the novel metal–organic frameworks (MOFs) adsorbent (Zr-DPHT) is prepared for the highly efficient and selective recovery of silver ions from wastewater. Experimental findings reveal that Zr-DPHT's adsorption of Ag(I) constitutes an endothermic process, with an optimal pH of 5 and exhibits a maximum adsorption capacity of 268.3 mg·g−1. Isotherm studies show that the adsorption of Ag(I) by Zr-DPHT is mainly monolayer chemical adsorption. Kinetic studies indicate that the internal diffusion of Ag(I) in Zr-DPHT may be the rate-limiting step. The mechanism for Ag(I) adsorption on Zr-DPHT involves electrostatic interactions and chelation. In competitive adsorption, Ag(I) has the largest partition coefficient (9.64 mL·mg−1), indicating a strong interaction between Zr-DPHT and Ag(I). It is proven in the adsorption–desorption cycle experiments that Zr-DPHT has good regeneration performance. The research results indicate that Zr-DPHT can serve as a potential adsorbent for efficiently and selectively capturing Ag(I), providing a new direction for MOFs in the recycling field of precious metals. [ABSTRACT FROM AUTHOR]

[Display omitted] Metal-organic frameworks (MOFs) have been widely studied for Cr(VI) adsorption in water. Theoretically, numerous MOFs can be synthesised by assembling diverse metals and ligands. However, the traditional manual experimentation for screening high-performance MOFs is resource-intensive and inefficient. A screening strategy for MOFs based on machine learning was proposed for the adsorption and removal of Cr(VI) from water. By collecting the characteristics of MOFs and the experimental parameters of Cr(VI) adsorption from the literature, a dataset was constructed to predict the adsorption performance. Among the six regression models, the model trained by the extreme gradient boosted tree algorithm had the best performance and was used to simulate the adsorption and screen potential high-performance adsorbents. Structure-property analysis indicated that prepared MOF adsorbents with properties of 0.37 < largest cavity diameter < 0.71 nm, 0.18 < pore volume < 0.57 cm3/g, 412 < specific surface area < 1588 m2/g, 0.43 < void fraction < 0.62 will achieve enhanced adsorption of Cr(VI) in water. High-performance adsorbents were successfully screened using a combination of machine-learning prediction and analysis. Experiments were conducted to verify the exceptional adsorption capacity of UiO-66 and MOF-801. This method effectively identified adsorbents and accelerated the development of new MOF adsorbents for contaminant removal, providing a novel approach for the discovery of superior adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe-based Metal-Organic Framework material (activated MIL-88A) efficiently removes various arsenic species in water. • Pseudo-second order kinetic model reveals chemisorption as the dominant mechanism. • Molecular shapes and sizes of arsenic species affect their adsorption rates to activated MIL-88A. • Activated MIL-88A shows high adsorption capabilities across a wide pH range. • Coordination and hydrogen bonding are the main mechanisms for arsenic adsorption. Arsenic in water environment can present significant threats to human health, and eliminating arsenic pollutants from wastewater is crucial. Based on our previously reported work, this study delved into the adsorption behavior and mechanism of different arsenic contaminants (p -ASA, ROX, As(V), and DMA) on the activated Fe-based metal–organic framework (activated MIL-88A). The results show that activated MIL-88A exhibits exceptional adsorption capabilities toward diverse arsenic pollutants. The adsorption process is endothermic, spontaneous, and viable, and chemical adsorption plays a leading role. The remarkable adsorption capacity of activated MIL-88A to various arsenic pollutants is primarily attributed to coordination, while hydrogen bonding also assumes a significant role in the elimination of p -ASA and ROX. Additionally, we investigated the impact of arsenic molecule shape and size, solution pH, and the existence of specific anions and dissolved organic matter (DOM) on the adsorption of different arsenic pollutants. This study can provide valuable insights for further exploring the selective adsorption of different kinds of arsenic species by Fe-based MOF materials and improving the adsorption efficiency of MOFs. [ABSTRACT FROM AUTHOR]

[Display omitted] A high surface area (883 m2·g−1) nanocomposite composed of an amine-functionalized metal–organic framework (NH 2 -UiO-66 (U6N)) and manganese dioxide (MnO 2 @U6N) was prepared as bifunctional adsorbent-catalyst for the purification of multiple aromatic volatile organic compounds (VOCs) such as benzene (B), toluene (T), m-xylene (X), and styrene (S), i.e., BTXS. The performance of MnO 2 @U6N was assessed for BTXS removal both as single- and multi-component systems at room temperature (RT (20 °C)) under dark conditions. MnO 2 @U6N exhibited superior catalytic-adsorption activity for the RT removal of BTXS. The removal performance of MnO 2 @U6N against BTXS was then assessed across varying levels of flow rate, VOC concentration, adsorbent/catalyst mass, and relative humidity. To better understand the catalytic-adsorption activity, two types of non-linear kinetic models (pseudo-first-order and pseudo-second-order) were utilized to simulate the experimentally obtained data. In-situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) analysis was also conducted to interpret the removal mechanism of BTXS. Their adsorption capacity (mg·g−1) values are estimated to increase in the order of B (21.1) < T (66.0) < X (79.1) < S (129.7). It is suggested that the adsorbed aromatic VOC molecules on the surface of MnO 2 @U6N should react with active oxygen species (lattice and adsorbed oxygen) to yield the environmentally benigh end products (i.e., carbon dioxide and water) along with various intermediates (e.g., alkoxides, aldehydes, phenolates, carboxylates, and anhydrides). Accordingly, the VOC removal potential of MnO 2 @U6N has been validated through the synergistic combination between adsorption (primary process) and catalysis (subordinate process) at RT. [ABSTRACT FROM AUTHOR]

[Display omitted] The rapid development of process technology has led to rapid daily industrial production, which also produced a large amount of waste liquid. At the same time, the existing treatment technology cannot keep up with the demand, resulting in the malicious destruction of the environment by wastewater, especially mercury-containing wastewater was very harmful. Effective means of removing mercury ions need to be found. With magnetic ferric oxide as the core and titanium-based metal–organic frameworks as the shell, a new type of magnetic adsorbent (BTA-MIL-125(Ti)@Fe 3 O 4) was synthesized. Materials were tested by multiple characterization methods and multiple sets of experiments. At optimal pH 6, the removal rate in 100 ppm Hg(Ⅱ) was as high as 95.8%. The theoretical adsorption capacity was 615 mg/L. Isothermal experiments, kinetic experiments and thermodynamic experiments have respectively verified that the material was a kind of adsorption material with self-emission heat based on chemical action and synergistic adsorption with Hill model. By simulating the immunity of a variety of ions (Cu, Zn, Mg, Ni, Cd), the material itself also exhibited a very high affinity for Hg(Ⅱ). The results of five high-cycle stable adsorption proved the repeatable stability of the material itself. Various characterization methods have also shown that nitrogen and sulfur-containing groups chelated with Hg(Ⅱ). All of the above was enough to show that the BTA-MIL-125(Ti)@Fe 3 O 4 was a magnetic adsorption material with excellent performance and great prospects. [ABSTRACT FROM AUTHOR]

[Display omitted] In the context of industrialization and severe wastewater pollution, mercury ions pose a major threat due to their high toxicity. However, traditional adsorbents and common metal-organic framework (MOF) materials have limited effectiveness. This study focuses on combining magnetic materials with functionalized titanium-based MOF composite (SNN-MIL-125(Ti)@Fe 3 O 4) to improve mercury ion adsorption. Through comprehensive characterization and analysis, the adsorption performance and mechanism of the material were studied. The optimal adsorption of the material was achieved at pH 5, exhibiting a pseudo-second-order adsorption model and the Hill theoretical capacity of 668.98 mg/g. Hill and Tempkin models confirmed the presence of chemical and physical adsorption sites on the material surface. Thermodynamic experiments showed a spontaneous endothermic process. Despite the presence of interfering ions, the material exhibited high selectivity for mercury ions. After four cycles, adsorption performance decreased by only 8%, indicating excellent reusability. Nitrogen- and sulfur-containing functional groups played a key role in mercury ion adsorption. In conclusion, SNN-MIL-125(Ti)@Fe 3 O 4 , as a magnetic MOF adsorption material, showed potential for effective remediation of mercury-contaminated wastewater. This study contributes to the development of efficient adsorption materials and enhances the understanding of their mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • Defective MIL-68(Al) was synthesized from waste PET plastic bottles. • d -MIL-68(Al) can remove nearly 97% of DMZ (C 0 = 100 mg L−1) in the first 10 s. • d -MIL-68(Al) exhibits the record adsorption kinetic constant of 2.84 g mg−1 min−1. • The DMZ adsorption capacity of d -MIL-68(Al) is 3 times of MIL-68(Al). • Defects in d -MIL-68(Al) create more active sites and promote mass transfer. In order to alleviate the pressure on the ecological environment and human health caused by wastewater of nitroimidazole antibiotics and poly(ethylene terephthalate) (PET) plastic waste, we propose a strategy of using defective MIL-68(Al) (d -MIL-68(Al)) derived from waste PET plastic for dimetridazole (DMZ) capture. The resulting d -MIL-68(Al) exhibits an excellent adsorption capacity of 555.6 mg g−1, which is three times of pristine MIL-68(Al) (181.8 mg g−1), demonstrating that the defective structures in d -MIL-68(Al) play a crucial role in the adsorption process. Remarkably, d -MIL-68(Al) can remove nearly 97% of DMZ in the first 10 s, and the removal efficiency reached 99% after adsorption equilibrium, affording a record kinetic rate constant k 2 (2.84 g mg−1 min−1). In short, d -MIL-68(Al) possesses both an ultrafast adsorption rate and outstanding adsorption capacity toward DMZ compared with reported adsorbents. Mechanism analysis reveals that the excellent DMZ adsorption performances can be ascribed to the abundant active sites caused by defective structures, as well as the π-π stacking and hydrogen bonding interactions between MOF and DMZ. Hence, d -MIL-68(Al) derived from waste PET plastic is an efficient porous adsorbent for rapid DMZ removal, which not only possesses great potential for wastewater treatment, but also reduces the harmful PET plastic waste, reflecting the concept of sustainable development. [ABSTRACT FROM AUTHOR]

[Display omitted] The development of effective adsorbents for the adsorption and removal of toxic selenite (SeO 3 2−) from wastewater is urgently required but challenging. Herein, formic acid (FA), a monocarboxylic acid, was used as a template to construct serial defective Zr-Fumarate (Fum) -FA based on a green and facile preparation method. Physicochemical characterization shows that the defect degree of Zr-Fum-FA can be flexibly controlled by regulating the amount of FA to be added. Owing to rich defect units, the diffusion and mass transfer of guest SeO 3 2− into the channel can be boosted. Particularly, Zr-Fum-FA-6 with the most defects exhibits superior adsorption capacity (519.6 mg g−1) and rapid adsorption equilibrium (∼200 min). The adsorption isotherms and kinetics can be well described by the Langmuir and pseudo-second-order kinetic models. Moreover, this adsorbent possesses excellent resistance towards co-existing ions, high chemical stability and good applicability in a broad pH range of 3–10. Thus, our study provides a promising adsorbent for SeO 3 2−, and more importantly, it proposes a strategy for rationally tailoring the adsorption behavior of adsorbents via defect construction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel binary MIL/ZIF hybrid adsorbents were successfully prepared for the first time. • The MIL/ZIF adsorbents can remove several antibiotics from wastewater efficiently. • The MIL/ZIF adsorbents can be applied to actual wastewater with high renewability. • A feasible adsorption mechanism was proposed for the removal of antibiotics. Environmental pollution by emerging contaminants has become an urgent problem. Herein, novel binary metal–organic framework hybrids were constructed from Materials of Institute Lavoisier-53(Fe) (MIL-53(Fe)) and zeolite imidazolate framework-8 (ZIF-8) for the first time. A battery of characterizations were employed to determine the MIL/ZIF hybrids' properties and morphology. Furthermore, the MIL/ZIF towards toxic antibiotics (tetracycline, ciprofloxacin and ofloxacin) were studied to explore their adsorption abilities. The present work disclosed that the obtained MIL-53(Fe)/ZIF-8 = 2:3 possessed an eminent specific surface area with an admirable removal efficiency of tetracycline (97.4%), ciprofloxacin (97.1%) and ofloxacin (92.4%), respectively. The tetracycline adsorption process conformed to the pseudo-second-order kinetic model and this process was more compatible with the Langmuir isotherm model with the highest adsorption capacity of 215.0 mg g−1. Moreover, the process of removing tetracycline was proved to be spontaneous and exothermic by the thermodynamic results. Furthermore, the MIL-53(Fe)/ZIF-8 = 2:3 towards tetracycline exhibited significant regeneration ability. The effects of pH, dosage, interfering ions and oscillation frequency on tetracycline adsorption capacity and removal efficiency were also investigated. The primary factors contributing to the decent adsorption ability between MIL-53(Fe)/ZIF-8 = 2:3 and tetracycline included electrostatic, π–π stacking, hydrogen bonding and weak coordination interactions. Additionally, we also investigated the adsorption ability in real wastewater. Thus, the proposed binary metal–organic framework hybrid materials can be deemed a promising adsorbent in wastewater purification. [ABSTRACT FROM AUTHOR]

[Display omitted] The removal of Cr(VI) and Pb(II) from wastewater is one of the methods to ensure water safety. However, it is still a difficult point to design efficient and selective adsorbent. In this work, Cr(VI) and Pb(II) were removed from water by a new metal–organic frameworks material (MOF-DFSA) with numerous adsorption sites. The max adsorption capacities of MOF-DFSA were 188.12 mg/g for Cr(VI) after 120 min and 349.09 mg/g for Pb(II) within 30 min. MOF-DFSA showed good selectivity and reusability after four cycles. The adsorption of MOF-DFSA was an irreversible process with multi-site coordination, and an active site adsorbed 1.798 Cr (VI) and 0.395 Pb (II). Kinetic fitting showed that the adsorption was chemisorption and surface diffusion was the main limiting step. Thermodynamic showed that Cr(VI) adsorption was enhanced at higher temperatures by spontaneous processes while Pb(II) was weakened. The chelation and electrostatic interaction of the hydroxyl and nitrogen-containing groups of MOF-DFSA with Cr(VI) and Pb(II) is the predominant mechanism, while the reduction of Cr(VI) also play an important role in adsorption. In conclusion, MOF-DFSA was a sorbent that can be used for the removal of Cr(VI) and Pb(II). [ABSTRACT FROM AUTHOR]

[Display omitted] This work reports the incorporation of coordinated water into Ni-BTC nanorods (Ni-BTC-O) which induces their structural transformation to Ni-BTC nanofibres (Ni-BTC-F). The carbonization of the Ni-BTC nanofibres at 600 °C results in the formation of carbon nanotube (CNT)-decorated hierarchical porous nickel/carbon hybrid (labelled as Ni/C-600) with enlarged pores. In contrast, the Ni/C hybrid obtained from the carbonization of the original (unmodified) Ni-BTC nanorods (Ni-BTC-O) at 600 °C (labelled as Ni-BTC-O-600) exhibits smaller pore size and does not show the formation of CNTs. The Ni/C-600 hybrid derived from Ni-BTC-F shows a very high adsorption capacity of 686.8 mg g−1 toward methyl blue (MB) dye. This is approximately 4.8 times higher than the adsorption capacity of Ni-BTC-O-600 (144.1 mg g−1). The higher adsorption performance of Ni/C-600 relative to Ni-BTC-O-600 can be attributed to its larger pore volume, hierarchical porosity, and additional adsorption sites provided by the CNTs. In addition, the Ni/C-600 hybrid can maintain 90% of its adsorption capacity after 5 consecutive cycles, demonstrating its potential as an efficient and recyclable adsorbent for MB dye. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel PCN-222 MOF with large pore size and high water stability is reported. • PCN-222 adsorbed remarkably high amount of PFOS (2257 mg/g) from water. • Adsorption occurred via electrostatic and hydrophobic interaction, and H-bonding. • PFOS removal was affected by adsorbate pKa and adsorbent PZC factors. • Micelles were formed to improve removal rate at high PFOS concentration. Poly- and perfluoro alkyl substances (PFAS) are a group of man-made, notoriously persistent, and highly toxic contaminants in the environment reported worldwide. Many adsorbents including granular activated carbon, graphene, biochar, zeolites, and clay minerals have been tested for PFAS removal from water, but most of these materials suffer from high cost and/or poor removal performance. Here, we synthesized, characterized, and examined the efficiency of PCN-222(Fe), a new porous metal organic framework (MOF) with high water stability, for adsorptive removal of a frequently occurring PFAS, perfluorooctane sulfonate (PFOS), from water. The adsorption isotherm and kinetic studies revealed high PFOS adsorption capacity of PCN-222 (2257 mg/g), with rapid PFOS removal rate (within 30 min). The structure of PCN-222 was unaffected in water in the pH range of 2–10 but disintegrated and lost its PFOS removal ability at pH > 10. The PFOS adsorption on PCN-222 was an endothermic reaction. Electrostatic attraction was a dominant mechanism for PFOS adsorption at < 1694 mg/g PFOS concentration, while hydrophobic interaction accompanied with hydrogen-bonding was responsible at ≥ 1694 mg/g PFOS concentration. The interlayer morphology of PCN-222 did not change due to increasing PFOS loading. The findings of this study demonstrated superior features of PCN-222 over other conventional adsorbents for its potential application in removing PFOS from contaminated water to reduce PFOS transfer from water to living organisms. [ABSTRACT FROM AUTHOR]

[Display omitted] • MIL-88A adsorbent were synthesized under different conditions. • Activated MIL-88A adsorbent has excellent adsorption capacity for p -ASA. • The adsorption kinetics and isotherms follow pseudo-second-order and Langmuir models. • Coordination and hydrogen bonding dominate the adsorption process. Organic arsenic pollutant p -arsanilic acid (p -ASA) in wastewater can be converted into highly toxic inorganic arsenic under natural conditions, causing serious harm to the environment and human health. In this study, an Fe-based metal – organic framework (MOF) material, activated MIL-88A, was synthesized as an adsorbent to remove p -ASA in water. Various influencing factors in the material synthesis process, including temperature, time, solution, and annealing process, were investigated to obtain the optimal reaction conditions. The synthesized activated MIL-88A had great porosity and excellent adsorption capacity for p -ASA in a wide pH range (3 ∼ 10). When the pH of the solution was 6, the activated MIL-88A achieved a great adsorption capacity of 813 mg·g−1 for the p -ASA solution with an initial concentration of 0.334 mmol·L−1. In addition, it still had excellent adsorption capacity after 4 times of repeated usage and washing. The adsorption kinetics of p -ASA on the activated MIL-88A followed the pseudo-second-order models, and the adsorption isotherms can be fitted by the Langmuir models well. The adsorption behavior was spontaneous and endothermic, and was dominated by Fe-O-As coordination and hydrogen bonding. [ABSTRACT FROM AUTHOR]

[Display omitted] • MOF-808 adsorbed 939 mg/g PFOS from aqueous solution. • MOF-808 showed excellent stability in water in the pH range of 2 to 10. • Electrostatic attraction between MOF-808′s Zr cluster and PFOS's SO 3 – took place. • PFOS removal was the highest at equilibrium solution pH around 5. • Formation of micelles affected PFOS adsorption capacity on MOF-808. Perfluorooctane sulfonate (PFOS) is a highly persistent contaminant of emerging concern causing harmful effects to human and ecosystem health. In this study, a novel MOF-808 metal–organic framework (MOF) was prepared and evaluated for adsorptive removal of PFOS from aqueous solution. The MOF-808 had high specific surface area (SSA; 1610 m2/g) and was structurally stable in aqueous medium for 7 days under different pH conditions. The MOF-808 reached PFOS adsorption equilibrium within 30 min (at 500 mg/L initial PFOS) and attained the maximum adsorption capacity of 939 mg/g at pH 4.1 – 5.4 (with 50 – 500 mg/L initial PFOS). The PFOS adsorption capacity of MOF-808 was unaffected at pH 2 to 7, but gradually decreased at pH > 7. High SSA, favorable pore size and abundant active adsorption sites on MOF-808 triggered high PFOS adsorption onto the adsorbent. The PFOS adsorption process was endothermic and spontaneous in nature. Electrostatic interaction between the cationic central cluster ([Zr 6 O 4 (OH) 4 ]12+) of MOF-808 and PFOS anion was identified as the key mechanism of PFOS adsorption onto MOF-808, as evident from the infrared spectroscopic investigation of the adsorbent. This study suggests that MOF-808 can be considered as a highly efficient adsorbent for PFOS removal from water and warrants future research to evaluate the application and performance of the material under wastewater conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 3 O 4 @MOF-525 was synthesized via the secondary-growth approach. • Fe 3 O 4 @MOF-525 can efficiently remove tetracycline and diclofenac sodium from water. • The introduction of Fe 3 O 4 enhanced the separability and the adsorption performance. • The generation of 1O 2 enabled the in-situ photo-regeneration of Fe 3 O 4 @MOF-525. The functionalization of metal–organic frameworks (MOFs) is imperative and challenging for the development of practical MOF-based materials. Herein, a magnetically functionalized Zr-MOF (Fe 3 O 4 @MOF-525) was synthesized via secondary-growth approach to obtain an easily-separated and recyclable adsorbent for the removal of pharmaceuticals (tetracycline (TC) and diclofenac sodium (DF)). After loading Fe 3 O 4 nanoparticles (NPs), due to the increase of micropore volume and specific surface area caused by defects, the adsorption performance of Fe 3 O 4 @MOF-525 was improved. The kinetics could be described by the pseudo-second-order kinetic model. The different adsorption capacity and initial rate were attributed to the properties of the pharmaceuticals, including the molecular size and hydrophobicity/hydrophilicity. In isotherm experiments, the maximum adsorption capacities of DF and TC on Fe 3 O 4 @MOF-525 calculated by Sips model reached 745 and 277 mg·g−1, respectively. The thermodynamic studies indicated the adsorption was endothermic and spontaneous. The effect of pH suggested that electrostatic interaction, π-π interaction, anion-π interaction, and H-bonding were possibly involved in the adsorption process. The adsorbent was separated by magnetic and regenerated. Washed with ethanol, Fe 3 O 4 @MOF-525 remained about 80% adsorption capacity after four cycles. In-situ photo-regeneration under visible-light irradiation was another attractive method, where > 95% TC was degraded in 4 h. The reaction with scavengers revealed that 1O 2 was the dominant reactive species in our system, indicating the occurrence of Type II photosensitization. The separability, excellent adsorption performance, and recyclability of Fe 3 O 4 @MOF-525 may lead to its beneficial applications in water treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • La-MOFs was prepared by adjusting ligands for fluoride removal from water. • La-BDC material exhibits a high fluoride adsorption capacity of 171.7 mg/g. • Adsorbents have excellent performance with high stability and renewability. • Adsorption mechanism is proposed as ligand exchange and coordination. • La-MOFs is a potential adsorbent for practical application. Excess fluoride in water poses a threat to ecology and human health, which has attracted global attention. In this study, a series of lanthanum-based metal–organic frameworks (La-MOFs) were synthesized by varying the organic ligands (i.e. , terephthalic acid (BDC), trimesic acid (BTC), biphenyl-4,4-dicarboxylic acid (BPDC), 2,5-dihydroxyterephthalic acid (BHTA), and 1,2,4,5-benzenetetracarboxylic acid (PMA)) to control the microscopic structure of the MOFs and subsequently apply them for the removal of fluoride in water. The maximum capture capacities of La-BTC, La-BPDC, La-BHTA, La-PMA, and La-BDC at 298 K are 105.2, 125.9, 145.5, 158.9, and 171.7 mg g−1, respectively. The adsorption capacity is greater than most reported adsorbents. The adsorption isotherms of La-MOFs for fluoride are well fit to the Langmuir isotherm model. In addition, the adsorption kinetics of La-BTC, La-BPDC, La-BHTA, La-PMA, and La-BDC follows the pseudo-second-order kinetic model, and the kinetic rate-limiting step of adsorption is chemical adsorption. Thermodynamics revealed that temperature is favorable for the adsorption of fluoride. Meanwhile, La-BTC, La-BPDC, La-BHTA, La-PMA, and La-BDC are suitable for the removal of fluoride in a relatively wide pH range (4.0–9.0). Simultaneously, from X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis, electrostatic attraction and ligand exchange are identified as the main action mechanisms for the adsorption of fluoride of La-MOFs. The prepared La-MOFs are used as efficient adsorbents for removal of fluoride in actual water, indicating that they have great potential in removing fluoride in real and complex environmental water. This work provides a new strategy for designing adsorbents with adjustable microstructure and expected function to effectively recover fluorosis in water. [ABSTRACT FROM AUTHOR]

[Display omitted] • UiO-66-(COOH) 2 MOF and its modification by cupper and iron were synthesized. • Remarakable removal of diclofenac by prepared MOFs was observed. • Zr atoms are the major interaction sites for DCF as they have the higher charge than Cu and Fe. • Remval mechanism may be due to H- bonding and and metal- π interaction. Water pollution by pharmaceuticals is currently a great concern due to their ecological risks. In this study, zirconium-based metal–organic frameworks (UiO-66-(COOH) 2) were used for removal of the nonsteroidal anti-inflammatory drug (NSAID) diclofenac sodium (DCF). They have been synthesized using a hydrothermal method. Copper and iron metal ions were incorporated in the framework using post-synthetic modification techniques to produce UiO-66-(COOCu) 2 and UiO-66-(COOFe) 2. The resulted MOFs were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning/transmission electron microscopy, and Brunauer–Emmett–Teller. The effects of the pH, initial concentration, and adsorption time on the adsorption process of diclofenac were studied. The maximum adsorption capacities obtained on UiO-66-(COOH) 2 , UiO-66-(COOCu) 2 , and UiO-66-(COOFe) 2 were 480.5, 624.3, and 769.1 mg/g, respectively. The adsorption of diclofenac was found to be better fitted with Langmuir isotherm and pseudo-second-order kinetic models. The adsorption mechanism was investigated using XRD, FT-IR, density functional theory and Monte Carlo simulation, in which the latter method was used to calculate the adsorption energies and determine the possible interactions between diclofenac and the adsorbents. UiO-66-(COOH) 2 , UiO-66-(COOCu) 2 , and UiO-66-(COOFe) 2 exhibited good recyclability for diclofenac removal, which confirms the sustainability of these materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel MOF adsorbent was synthesized by post-synthesis modification NH 2 -UiO-66. • The maximum adsorption capacity of Au(III) is 683.45 mg/g at 298 K. • The adsorbent has excellent selectivity and reusability. • The adsorption mechanism is electrostatic attraction, reduction and chelation. Efficient removal of gold ions from wastewater has become a hot research topic. A new metal–organic framework material (PAR-UiO-66) was prepared by post-modification of UiO-66-NH 2. A series of characterizations proved the successful preparation of PAR-UiO-66. The batch adsorption experiment was carried out. Under the room temperature (298 K) of and pH 4.0, the optimal adsorption capacity of PAR-UiO-66 for gold ions was 683.45 mg/g, which was an increase of 426.8 mg/g compared with that of UiO-66-NH 2. The adsorption of gold ions on PAR-UiO-66 accords with pseudo-second-order kinetics and Langmuir isotherm modles. The adsorption process was endothermic and spontaneous. PAR-UiO-66 has good selectivity and still has 92.5% adsorption efficiency after five repeated adsorptions. The adsorption mechanism is electrostatic attraction, reduction and chelation. [ABSTRACT FROM AUTHOR]