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Abstract Vascularization plays a significant role in promoting the expedited process of bone regeneration while also enhancing the stability and viability of artificial bone implants. Although titanium alloy scaffolds were designed to mimic the porous structure of human bone tissues to facilitate vascularization in bone repair, their biological inertness restricted their broader utilization. The unique attribute of Metal-organic framework (MOF) MIL-53(Fe), known as “breathing”, can facilitate the efficient adsorption of extracellular matrix proteins and thus provide the possibility for efficient interaction between scaffolds and cell adhesion molecules, which helps improve the bioactivity of the titanium alloy scaffolds. In this study, MIL-53(Fe) was synthesized in situ on the scaffold after hydrothermal treatment. The MIL-53(Fe) endowed the scaffold with superior protein absorption ability and preferable biocompatibility. The scaffolds have been shown to possess favorable osteogenesis and angiogenesis inducibility. It was indicated that MIL-53(Fe) modulated the mechanotransduction process of endothelial cells and induced increased cell stiffness by promoting the adsorption of adhesion-mediating extracellular matrix proteins to the scaffold, such as laminin, fibronectin, and perlecan et al., which contributed to the activation of the endothelial tip cell phenotype at sprouting angiogenesis. Therefore, this study effectively leveraged the intrinsic “breathing” properties of MIL-53 (Fe) to enhance the interaction between titanium alloy scaffolds and vascular endothelial cells, thereby facilitating the vascularization inducibility of the scaffold, particularly during the sprouting angiogenesis phase. This study indicates that MIL-53(Fe) coating represents a promising strategy to facilitate accelerated and sufficient vascularization and uncovers the scaffold-vessel interaction from a biomechanical perspective. Graphical Abstract

Vascularization plays a significant role in promoting the expedited process of bone regeneration while also enhancing the stability and viability of artificial bone implants. Although titanium alloy scaffolds were designed to mimic the porous structure of human bone tissues to facilitate vascularization in bone repair, their biological inertness restricted their broader utilization. The unique attribute of Metal-organic framework (MOF) MIL-53(Fe), known as "breathing", can facilitate the efficient adsorption of extracellular matrix proteins and thus provide the possibility for efficient interaction between scaffolds and cell adhesion molecules, which helps improve the bioactivity of the titanium alloy scaffolds. In this study, MIL-53(Fe) was synthesized in situ on the scaffold after hydrothermal treatment. The MIL-53(Fe) endowed the scaffold with superior protein absorption ability and preferable biocompatibility. The scaffolds have been shown to possess favorable osteogenesis and angiogenesis inducibility. It was indicated that MIL-53(Fe) modulated the mechanotransduction process of endothelial cells and induced increased cell stiffness by promoting the adsorption of adhesion-mediating extracellular matrix proteins to the scaffold, such as laminin, fibronectin, and perlecan et al., which contributed to the activation of the endothelial tip cell phenotype at sprouting angiogenesis. Therefore, this study effectively leveraged the intrinsic "breathing" properties of MIL-53 (Fe) to enhance the interaction between titanium alloy scaffolds and vascular endothelial cells, thereby facilitating the vascularization inducibility of the scaffold, particularly during the sprouting angiogenesis phase. This study indicates that MIL-53(Fe) coating represents a promising strategy to facilitate accelerated and sufficient vascularization and uncovers the scaffold-vessel interaction from a biomechanical perspective. [ABSTRACT FROM AUTHOR]

In this paper, a high‐performance composite nanofiber membrane with excellent air filtration and dye degradation properties was prepared by incorporating MIL‐53(Fe) nanoparticles into the electrospinning solution. The results showed that the filtration efficiency for PM2.5 of the PP/PVDF‐HFP/MIL‐53(Fe) composite nanofiber membrane reached up to 99.3% with the addition of 2 wt% MIL‐53(Fe). Moreover, the composite nanofiber membrane exhibited steady filtration efficiency across different parameters, including air velocity, PM2.5 concentration, and extended testing time. Furthermore, the incorporation of MIL‐53(Fe) significantly enhanced the removal efficiency of the composite nanofiber membrane toward Rh B, resulting in a remarkable 91% removal rate. The polymer/MOF composite nanofiber membranes prepared by simple and cheap electrospinning technology have a wide range of practical applications in the field of environmental protection. Highlights: PPM composite nanofiber membrane was prepared via electrospinning method.MIL‐53(Fe) nanoparticles were introduced to PPM composite nanofiber membrane.PPM composite nanofiber membrane showed excellent removal efficiency for PM2.5.PPM composite nanofiber showed a good removal performance for RhB in solution. [ABSTRACT FROM AUTHOR]

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Organic semiconductors are promising materials for the photocatalytic treatment of pollutants and organic synthesis. Herein, MIL-53(Fe)@perylene diimide (PDI) organic heterojunctions were constructed by ultrasonic assembly using PDI as the co-catalyst, and PDI organic supramolecular material was uniformly distributed on the surfaces of MIL-53(Fe). The most effective M53@PDI-20 organic heterojunctions achieved 72.7% photodegradation of rhodamine B (10 mg/L) within 50 min and a 99.9% reduction in Cr(VI) (10 mg/L) for 150 min, and the corresponding apparent degradation rate constants were higher than a single component. Meanwhile, the conversion rate of benzyl alcohol over M53@PDI-20 achieved 91.5% for 5 h with a selectivity of above 90% under visible light exposure, which was more than double that of PDI. The well-matched band structures and the strong π–π bonding interactions between MIL-53(Fe) and PDI can increase the electron delocalization effect to facilitate the transfer and separation of photogenerated carriers. Lots of oxidative reactive species (h+, •O2− and •OH) also played a great contribution to the strong oxidation capacity over the heterojunctions system. This work suggests that MIL-53(Fe)@PDI organic heterojunctions may be a promising material for pollutant removal and organic synthesis. [ABSTRACT FROM AUTHOR]

MIL-53(Fe) was prepared and modified with benzoic acid to prepare MIL-53(Fe)-BA additive, which was used to improve the catalytic oxidation rate of sulfite, prevent the scaling of the desulfurization tower, and improve the desulfurization efficiency during the wet flue gas desulfurization (WFGD) process of power plants. MIL-53(Fe)-BA exhibits abundant Lewis acid sites because of the appearance of coordination unsaturated Fe atoms. Due to the excellent sorption capacity, Ca(OH)2 was used as the main SO2 desulfurizer. The composite desulfurizers were prepared by mixing MIL-53(Fe)-based additives and Ca(OH)2, and were characterized by SEM, XRD, and FT-IR. A desulfurization unit was set up at laboratory scale to study the effect of catalytic oxidation additives on sulfite oxidation and desulfurization efficiency. The results showed that the addition of MIL-53(Fe)-BA can increase the oxidation capacity of sulfite by 159%, and greatly improve the desulfurization efficiency. These composite desulfurizers broaden the adaptability of the desulfurizing system to high-sulfur coals, and provide support for improving the desulfurizing efficiency of power plants. [ABSTRACT FROM AUTHOR]

As a new type of porous crystal nanomaterials, metal–organic frameworks (MOFs) have testified potential for various applications, particularly photocatalysis in recent years. However, their photocatalytic applications are still limited due to the rapid recombination rate of charge carriers. In this study, a facile method was developed successfully to greatly boost the sunlight-driven photocatalytic activity of a MOF material (MIL-53(Fe)) by construction of a hybrid with MoSe2 nanoparticles via a facile one-step hydrothermal method. The prepared catalysts were characterized in detail, and their photocatalytic performances were evaluated via degradation of rhodamine B (RhB) and tetracycline (TC). The results revealed that the constructed MIL-53(Fe)/MoSe2 hybrid exhibited tremendously enhanced photocatalytic activity. The optimal MMS-4 photocatalyst displayed the best photocatalytic activity, and its degradation efficiencies for RhB and TC were 13 and 2 times higher than that of pristine MIL-53(Fe), respectively. More interestingly, its photocatalytic performance was much superior to previously reported MIL-53(Fe)-based photocatalysts. The significantly improved catalytic performances are attributed to the formed hybrid with well-matched energy bands which greatly facilitates the transfer and separation of charge carriers, decrease band gap, and increase light absorption. This work presents a new strategy to highly improve the photocatalytic performance of MOF nanomaterials and facilitate their applications for high-efficiency removal of organic pollutants. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are commonly utilized for environmental remediation because of their exceptional physicochemical characteristics. This study synthesized GO@MIL-53(Fe) (MFG 2 %) using the solvothermal approach to remove tetracycline from water. The composites were evaluated utilizing several material characterization techniques, including XRD, BET, SEM, etc. The study found that the most effective synthesis of MFG 2 % occurred with a mass ratio of Fe:GO=100:2, a temperature of 150 °C, and a hydrothermal time of 24 h. This resulted in a 91.6 % removal of tetracycline after a 45-minute dark reaction followed by a 75-minute light reaction using a 400 W mercury lamp with a wavelength of 365 nm. In comparison, the degradation rate of tetracycline by MIL-53(Fe) (MFG 0 %) under identical conditions was 75.6 %. Meanwhile, MFG 2 % demonstrated remarkable adsorption-photocatalytic synergism. The enhanced efficiency of MFG 2 % was mostly due to the incorporation of graphene oxide (GO), which expanded the light absorption range of the material. Additionally, the high electrical conductivity of GO enhanced the active site of the photocatalytic reaction and increased the quantum yield. The ESR characterization and quenching studies revealed that three radicals, •O 2 -, h+, and •OH, participated in the degradation procedure. The principal active component is •O 2 -. This paper introduces a novel method for doping modification of MOF-like materials and the breakdown of tetracycline. [Display omitted] • Successful synthesis of GO@MIL-53(Fe) (MFG 2 %) composite catalysts. • Composite catalysts for tetracycline degradation over a wide concentration range. • Good stability and recyclability of composite catalysts. • Composite catalyst has significant adsorption-photocatalytic synergistic effect. • Composite catalyst has good mineralization effect on tetracycline. [ABSTRACT FROM AUTHOR]

The photocatalytic technology based on Metal-Organic Frameworks (MOFs) has shown promising applications in the field of antibiotic pollution control. However, it still faces challenges in efficiently removing high-concentration antibiotic wastewater. A typical Fe-containing MOF, MIL-53(Fe), was successfully synthesized and demonstrated efficient photocatalytic activity under visible light irradiation for high-concentrations of tetracycline hydrochloride (TCH). However, the bare MIL-53(Fe) exhibited unsatisfactory photocatalytic performance. To overcome the low degradation efficiency resulting from the rapid recombination of light-induced electron-hole pairs, H 2 O 2 was introduced as an external electron acceptor to establish a synergistic Fenton-like system to couple with the photocatalysis process. The results showed that in the MIL-53(Fe)/H 2 O 2 /Vis system, 99% of 1 g/L TCH was degraded within 80 min, while the degradation efficiency of the MIL-53(Fe)/Vis process was only 4.89% under identical conditions. The degradation mechanism of the coupling system was performed by radical scavenging experiments and Electron Spin Resonance characterization. The results indicated that ·OH was the dominant radical in the coupled reaction, and ·O 2 - and h+ also played a role in this system. The significant improvement in TCH degradation efficiency during the coupling process was attributed to the following three factors: (1) In the coupling reaction process, photo-generated electrons can stimulate H 2 O 2 to form ·OH radicals, inhibiting the recombination of photo-generated electrons and holes, improving the efficiency of the photocatalytic reaction. (2) FeIII in MIL-53(Fe) can be excited by photo-generated electrons and converted to FeII, which then stimulates H 2 O 2 to form ·OH radicals. (3) FeIII in MIL-53(Fe) can convert with FeII, stimulate H 2 O 2 to form ·OH radicals, and participate in the degradation reaction. In addition, the reusability and stability of the MIL-53(Fe) photocatalyst in the coupled system, as well as the impact of operational parameters, were systematically studied. This work demonstrates a feasible strategy for environmental remediation by enhancing the efficiency of MIL-53(Fe) in photocatalytic Fenton-like systems, thereby providing a viable approach for the treatment of high-concentration antibiotic wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

This article prepared a series of MIL-53(Fe) implanted carbon spheres derived from resorcinol-formaldehyde resins for rapid adsorption of Ciprofloxacin (CIP) using a facile hydrothermal coupling calcination methodology. Results indicated that MIL53(Fe)@RF-800, which was calcined at 800 °C, demonstrated the highest CIP removal efficiency of up to 95% within 60 min in batch adsorption tests. Moreover, MIL53(Fe) @RF-800 could remove over 95.8% of CIP at an amount of 0.2 mg/L, while both Cl− and HCO 3 − had a negligible impact on the CIP adsorption. It is noteworthy that when there was NO 3 − or SO 4 2− in the solution, the impact of CIP adsorption displayed an inhibitory trend overall. In addition, MIL53(Fe)@RF-800 exhibited a broad pH range adaptability (over 95% CIP removal efficiency at pH = 3.0–10.5), even under highly acidic (pH < 3.0) or alkaline (pH > 10.5) conditions, the adsorption capacity for CIP was greater than 85%. In conclusion, this study provides novel insights into the development of highly porous MIL-53(Fe)-based adsorbent for rapid and pH-unrestricted adsorption of antibiotics and offers the possibility of practical engineering applications. [Display omitted] • MIL-53(Fe) implanted carbon spheres were synthesized for rapid adsorption of antibiotics. • MIL53(Fe)@RF-800 showed excellent pH-adaptability (>95% CIP removal rate at pH = 3.0–10.5). • The adsorbent overcomes the challenge of CIP removal within neutral pH. [ABSTRACT FROM AUTHOR]

[Display omitted] In this study, based on one-step hydrothermal method, boron nitride nanosheets (BNNs) and MIL-53(Fe) composites (BNFe-X) were successfully prepared and the catalytic performance of BNFe-X on persulfate (PS) activation for ibuprofen (IBP) photodegradation was investigated. The introduction of BNNs changed the morphology of MIL-53(Fe) to be a unique prism-like structure and enhanced the degradation efficiency of IBP, which followed the pseudo-first-order rate kinetics. Among the prepared composites, BNFe-3 (3% BNNs) exhibited the highest IBP degradation activity and possessed strong stability after four cycles. Over 99% IBP removal was achieved at the irradiation time of 60 min. The promoted decomposition rate of IBP could be ascribed to be the activation of PS and the enhanced electrons transfer efficiency between BNNs and MIL-53(Fe). The scavenger studies and electron spin-resonance spectroscopy (ESR) demonstrated the generation of SO 2 -, OH and O 2 -, and all these radicals had the different contributions in IBP degradation. Based on the LC-MS-MS and TOC results, the possible decomposition pathways of IBP in BNFe-3/PS system were proposed. This work suggested that the BNNs/Fe-based MOFs composites and PS system had great potential in organic pollutants degradation in aqueous solution. [ABSTRACT FROM AUTHOR]

The application of metal organic frameworks (MOFs) in electrochemical sensing has aroused great interest. However, it is still a great challenge to improve their poor conductivity. Here, we reported a novel phenol electrochemical sensor based on Fe2O3/MIL-53(Fe)/rGO, which was fabricated by the thermal decomposition of MIL-53(Fe). The composition and morphology of Fe2O3/MIL-53(Fe)/rGO were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), SEM, and mapping analysis. Meanwhile, the electrochemical behaviors of phenol on the Fe2O3/MIL-53(Fe)/rGO/GCE were investigated by cyclic voltammetry and linear sweep voltammetry. Under optimized conditions, Fe2O3/MIL-53(Fe)/rGO/GCE had enhanced electrocatalytic activity toward phenol due to the larger surface area and excellent conductivity of the Fe2O3/MIL-53(Fe)/rGO. The electrochemical sensor exhibited a wide linear range (0.5–600 μM) and a low detection limit (0.1 μM) as well as good reproducibility and stability. The proposed sensor has also been applied for the determination of phenol in the refinery wastewater samples with satisfactory results. [ABSTRACT FROM AUTHOR]

The establishment of heterojunctions was considered as an exceptional strategy to obtain high-efficiency charge separation and enhanced photocatalytic performance. Herein, a series of FePMo/MIL-53(Fe) (FeM-53) heterojunctions were successfully constructed through in-situ growth of FePMo onto MIL-53(Fe) surface and their photocatalytic capacity were examined by visible-light-induced Cr(VI) reduction. Interestingly, the as-fabricated composites offered various photocatalytic activities controllably relying on the mass ratio of FePMo to MIL-53(Fe). Particularly, the one with the 10% ratio displayed the highest Cr(VI) reduction rate (100%) within 75 min, which was respectively over 4 and 2 folds higher than pure FePMo and MIL-53(Fe). The boosted photoactivity might be ascribed to the establishment of S-scheme heterojunction with suitable band alignment between FePMo and MIL-53(Fe), which broadened the light absorption range and improved charge separation. Further mechanism investigations implied both •O 2 − and e− were the key reactive species for Cr(VI) removal. Besides, the composite preserved excellent stability after 4 consecutive tests, and performed well in the presence of organic dyes. Such a S-scheme heterojunction may promise for highly efficient environmental mitigation. [Display omitted] • A novel FePMo/MIL-53(Fe) S-scheme heterojunction was fabricated. • The composite has enhanced visible light absorption and charge separation rate. • Superior activity and stability with Cr(VI) reduction rate of 100% was obtained. • S-scheme heterojunction greatly boosted charge separation and ROS production. [ABSTRACT FROM AUTHOR]

MIL-53(Fe) was prepared and modified with benzoic acid to prepare MIL-53(Fe)-BA additive, which was used to improve the catalytic oxidation rate of sulfite, prevent the scaling of the desulfurization tower, and improve the desulfurization efficiency during the wet flue gas desulfurization (WFGD) process of power plants. MIL-53(Fe)-BA exhibits abundant Lewis acid sites because of the appearance of coordination unsaturated Fe atoms. Due to the excellent sorption capacity, Ca(OH)2 was used as the main SO2 desulfurizer. The composite desulfurizers were prepared by mixing MIL-53(Fe)-based additives and Ca(OH)2, and were characterized by SEM, XRD, and FT-IR. A desulfurization unit was set up at laboratory scale to study the effect of catalytic oxidation additives on sulfite oxidation and desulfurization efficiency. The results showed that the addition of MIL-53(Fe)-BA can increase the oxidation capacity of sulfite by 159%, and greatly improve the desulfurization efficiency. These composite desulfurizers broaden the adaptability of the desulfurizing system to high-sulfur coals, and provide support for improving the desulfurizing efficiency of power plants.

The impurity of salicylic acid (SA) in aspirin is a required inspection item for drug quality control. Since free SA is significantly toxic for humans, the content determination of free SA is absolutely necessary to ensure people's health. In this work, a facile colorimetric method was developed for the detection of SA in aspirin by utilizing the MIL-53(Fe) nanozyme. As MIL-53(Fe) possesses enzyme mimicking catalytic activity, 3,3,5,5-tetramethylbenzidine (TMB) can be easily oxidized to blue-oxidized TMB (oxTMB) with the existence of H2O2. Moreover, an inhibition effect on the catalytic activity of the MIL-53(Fe) nanozyme is induced due to the specific complexation between SA and Fe3+ in the center of MIL-53(Fe), which results in a lighter color in the oxTMB. The color change of oxTMB can be seen easily by the naked eye with the addition of different concentrations of SA. Thus, a simple colorimetric platform was established for effectively monitoring SA. A good linear relationship (R2 = 0.9990) was obtained in the concentration range of 0.4–28 μmol L−1, and the detection limit was 0.26 μmol L−1. In particular, the rationally designed system has been well-applied to the detection of SA impurity in aspirin. Satisfyingly, the detection results are highly in accord with those of HPLC. This novel colorimetric platform broadens the application prospects of nanozymes in the field of pharmaceutical analysis.

In this work, the effects of preparation methods such as CE oven, microwave irradiation, and ultrasound on the morphology, particle size and crystallinity of MIL-53(Fe) are firstly investigated. Furthermore, the methods are utilized to prepare Pt NPs@MIL-53(Fe). As a result, well-defined Pt NPs@MIL-53(Fe) prepared by microwave irradiation exhibits uniformed morphology, high crystallinity, and high-disperse Pt NPs, which has been confirmed by FT-IR, TG, N2 adsorption at 77K, TEM and PXRD. Pt NPs@MIL-53(Fe) composite can selectively catalyze the thiophene hydrogenation over nitrobenzene and benzothiophene hydrogenation. The result shows that the sulfur amount can rapidly be reduced to less than 10 ppm and the crystallinity of reacted Pt NPs@MIL-53(Fe) is unchangeable.

• Mn-MIL-53(Fe) was synthesized by one-step solvothermal method. • The obtained Mn-MIL-53(Fe) could efficiently activate peroxymonosulfate (PMS). • Reaction parameters of Mn-MIL-53(Fe)/PMS system for TC degradation were optimized. • Possible mechanism of tetracycline (TC) degradation and TC degradation pathway were investigated proposed. • The Mn-MIL-53(Fe) system exhibited high efficiency in actual water. Herein, Mn-doped MIL-53(Fe) were fabricated via one-pot solvothermal method and used for peroxymonosulfate (PMS) activation towards tetracycline (TC) degradation from aqueous solution. The characterizations of SEM, FTIR and XRD were utilized to reveal the morphology and structure of the materials. The results showed that Mn-MIL-53(Fe)-0.3 displayed the optimal catalytic performance, the removal efficiency of TC could reach 93.2%. Moreover, the catalytic activity of Mn-MIL-53(Fe) towards TC under different initial pH values, co-existing anions (C l - , CO 3 2 - and SO 4 2 - ) and humic acid (HA) were investigated. The results of thermodynamic experiment suggested that the catalytic process was endothermic. In addition, integrated with capture experiments results and the characterization results of electron paramagnetic resonance (EPR), which revealed that SO 4 · - and H O - were the reactive radicals involving in the reaction. More importantly, the possible activation mechanism was discussed in detail based on the X-ray photoelectron spectroscopy results. The active species were generated by the active sites of Fe(II) and Mn(II) on Mn-MIL-53(Fe) effectively activated PMS. Furthermore, the degradation intermediates and possible degradation pathway were investigated by LC-MS. Finally, the catalyst also showed good performance in actual wastewater and demonstrated good recyclability. The Mn-MIL-53(Fe)/PMS system exhibited a promising application prospect for antibiotic-containing waste water treatment. [ABSTRACT FROM AUTHOR]

A novel yolk-shell Ag 3 PO 4 @MIL-53(Fe) Z-scheme photocatalyst was fabricated via a "bottle-around-ship" like method. Experiments on the treatment of tetracycline upon visible light irradiation showed that the as-prepared photocatalyst possessed excellent photocatalytic performance. Experimental results showed that tetracycline removal efficiency of the yolk-shell Ag 3 PO 4 @MIL-53(Fe) Z-scheme photocatalyst was almost 3 times higher than that of MIL-53(Fe). The enhanced photocatalytic performance of Ag 3 PO 4 @MIL-53(Fe) nanocomposite could be contributed to its higher surface area, better absorption capability, and greater charge separation efficiency. In addition, the H 2 O 2 concentration detection results for Ag 3 PO 4 (154 μmol/L) and Ag 3 PO 4 @MIL-53(Fe) (52 μmol/L) indicated that a big part of generated H 2 O 2 on the Ag 3 PO 4 core would be quickly decomposed by the MIL-53(Fe) shell and generated more reactive species through the photo-Fenton-like reaction, which is beneficial for the improvement of photocatalytic performance. This is a promising approach to fabricate yolk-shell structure photocatalyst and a different aspect to design multiple semiconductor composites heterojunction for environmental remediation. [ABSTRACT FROM AUTHOR]

• A coprecipitation method was applied to fabricate BiOBr/MIL-53(Fe) novel photocatalyst. • The MIL-53(Fe) doping endowed BiOBr with the stronger adsorption ability and higher utilization efficiency of visible light. • The heterojunction can be formed between MIL-53(Fe) and BiOBr to enhance the photocatalytic degradation performance. • The degradation pathway of carbamazepine was put forward based on the experimental results. In this work, a series of BiOBr/MIL-53(Fe) hybrid photocatalysts have prepared by a facile co-precipitation method. Rhodamine B (RhB) and carbamazepine (CBZ) were selected as the targets to evaluate the visible-light photocatalytic activity of the prepared samples. All of the hybrids exhibited better catalytic performance compared to the pristine BiOBr, and the performance of BiOBr/MIL-53 (with 20 wt% of MIL-53) was the most efficient. The excellent performance can be contributed to the incorporation of MIL-53(Fe) which not only form the heterojunction with BiOBr to inhibit the recombination of the photoinduced electron-hole pairs, but also utilize the visible light more effectively. The photocatalytic mechanism was studied, it shows that OH and h+ were both the main active species for the degradation of contaminants. Moreover, the degradation pathways of CBZ via the photocatalysis over BiOBr/MIL-53(Fe) hybrid were presented based on the determination of LC–MS/MS and the results of catalytic mechanisms. With the recent increase in reported MOFs materials, we believe a new class of hybrid catalytic materials is possible. This result is conceptually interesting as it opens the door to various MOF-based BiOBr materials for environmental purification and restoration. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • TSMF heterojunction was implemented as a visible-light-driven photocatalyst. • The TSMF heterostructures enhanced the separation of photoexcited carriers. • The addition of 1T-MoS 2 changes the structure and morphology of MOFs. • The addition of 1T-MoS 2 significantly boosts the surface area of MOFs. Abstract High photocatalytic hole-electron pairs separation efficiency and the wide use of inexpensive and earth-abundant materials as cocatalysts in most semiconductor-based photocatalytic systems are desired for improving the photocatalytic activity and practical application. Herein, we report a facile one-pot solvothermal approach of integrating stable metallic nonmetal materials 1T-MoS 2 nanosheets with MIL-53(Fe) to form needle-shaped 1T-MoS 2 @MIL-53(Fe) (TSMF) composites. Interestingly, the introduction of 1T-MoS 2 turns nonspecial-structured MIL-53(Fe) into needle-like structure and the BET analysis reveals that the optimal TSMF composites possess abundant coexistence of micropores and mesopores with a large surface area of 337 m2 g−1, which is about 16 folds higher than that of the pure MOFs. Meanwhile, it is remarkable that the photocatalytic rate of ibuprofen (IBP) by optimal TSMF nanocomposites has improved 7.5 and 9.4 times compared to the pristine MIL-53(Fe) and 1T-MoS 2 , respectively. The photocatalytic efficiency of TSMF composites enhances due to the emerging micropores, which can provide more adsorption and reaction sites. In addition, the formed compact and uniform interface contact between 1T-MoS 2 sheets and MOF may dramatically accelerate the separation of the photo-induced charges, thus enhance the photocatalytic activity. We also study the photocatalytic mechanism combined the corresponding electrochemical testing and the photo-degradation intermediates identified by ion chromatography (IC) and LC–MS-MS, indicating that superoxide radicals (O 2 –), hydroxyl radical (OH) and electrons (e−) are the main active radicals in IBP photocatalysis and decarboxylation and hydroxylation are the main degradation pathways of IBP. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrothermal synthesis method is used to prepared the double cone hexagonal prism shape MIL-53(Fe) NPs. • Choline chloride–ethylene glycol DES is encapsulated on hydrophilic MIL-53(Fe) nanoparticles. • The DES-coated MIL-53(Fe) is incorporated in PVDF pervaporative MMMs for phenol removal study. • The hydrophilicity of DES@MIL-53(Fe) nanoparticles can be attributed to significant boost in water flux. • The observed water flux and phenol removal of A4 membrane is 126 L m−2h−1 and 93.85%, respectively. Novel hydrophilic pervaporative mixed matrix membranes (MMMs), comprising deep eutectic solvent-coated MIL-53(Fe) embedded polyvinylidenefluoride (PVDF) matrix, are prepared to remove phenol from the water. Double cone hexagonal prism type MIL-53(Fe) nanofillers are first synthesized by hydrothermal method and then encapsulated with deep eutectic solvent (DES) solution by a deep coating process. The DES-coated MIL-53(Fe) nanofillers are added to the PVDF matrix to prepare the MMMs using the non-solvent-induced phase-separation (NIPS) process. The prepared DES@MIL-53(Fe) and MMMs are characterized by various analytic techniques to verify the successful addition of the nanofillers into the PVDF matrix. The highest pure water flux (PWF) values of nearly 126 L m−2h−1 are observed with a DES@MIL-53(Fe) loading of 7.5 wt% in the polymer dope solution for MMMs, which is three times higher than pure PVDF membrane values (41.5 L m−2h−1). The DES@MIL-53(Fe)/PVDF MMMs showed nearly 215% enhancement in pure water flux (131.66 L m−2h−1) and ∼ 107% enhancement in the phenol removal efficiency (93.22%) for the 50-ppm phenol solution as compared to pure PVDF membranes. Further, the experiments are carried out within a wide range of feed concentrations (feed concentration: 15–90 ppm) and feed pH (pH: 1–13) to study the separation performance of the MMMs. [ABSTRACT FROM AUTHOR]

The complicated oily wastewater containing hazardous organics post a great challenge to the membrane separation technology. Herein, a multilayer porous multifunctional MXene/MOF composite membrane with high permeability and photocatalytic degradation performance was prepared by embedding rod-shaped MIL-53(Fe) into layered MXene nanosheets and self-assembling them onto porous polyacrylonitrile fibrous mat. It was found that the embedment of rod-like MIL-53(Fe) with rough nanostructures could effectively avoid the dense physical stacking of MXene nanosheets and regulate the layer spacing, which was conducive to the enhancement of water channel and permeability of membrane. Moreover, the hydrophilic modification of TA could render the super-wetting feature (WCA=0°, UOCA>150°) and enhance the oil resistance of the membrane. Thence, the composite membrane exhibited favorable separation flux (904.3 ∼ 1226.5 L·m−2·h−1) and retention rate (99.06 ∼ 99.62%) for different O/W emulsions. In addition, the coupling of rod-like MIL-53(Fe) and MXene nanosheets endowed the composite membrane with efficient photocatalytic performance, which could degrade various dyes contained in oily wastewater (CV: 62.4%, MeB: 99.0%, CR: 79.5%, MO: 84.1%). Overall, this study opens up a new way for the preparation of super-wetting and multi-functional fibrous composite membrane, showing the broad application prospects in the purification of multi-component oily wastewater. [Display omitted] • Novel rod-like MIL-53(Fe) intercalated MXene lamellar membrane was fabricated. • The interlayer spacing and wettability (WCA=0°, UOCA>150°) can be well regulated. • The high permeability (up 1226.5 L·m−2·h−1) for O/W emulsions was achieved. • The membrane offered efficient photocatalytic degradation for MeB (99.0%). [ABSTRACT FROM AUTHOR]

Novel metal-organic framework/stannous sulfide (MIL-53(Fe)/SnS) nanocomposite photocatalysts were successfully synthesized by a one-step deposition process. The structure, composition and optical properties of the MIL-53(Fe)/SnS composite were systematically characterized by the X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, Fourier transform-infrared spectroscopy, UV–vis diffuse reflection spectroscopy and photoluminescence analysis. The photocatalytic performance of MIL-53(Fe)/SnS composite has been evaluated in the reduction of chromium (VI) under visible-light irradiation. Compared with pure MIL-53(Fe) and SnS, the MIL-53(Fe)/SnS composite exhibited enhanced photoreduction capability of chromium (VI) due to the strengthened absorption in the visible region, higher electron-hole separation rate and larger specific area. The MIL-53(Fe)/SnS composite with MIL-53(Fe) adding of 15 mg displayed optimal chromium (VI) reduction rate of 0.01878 min −1 , which was about 7.5 and 5.2 times than pure MIL-53(Fe) and SnS, respectively. The active species superoxide radical ( O 2 – ), electron(e − ) and hole(h + ) are essential toward chromium (VI) reduction. Lastly, a possible photocatalytic mechanism is proposed. [ABSTRACT FROM AUTHOR]

A novel system combining photocatalysis and capacitive deionization (CDI) was proposed and used to efficiently remove the total Cr from the aqueous solution for the first time. MIL-53(Fe) with wide visible-light absorption was successfully prepared by a simple solvothermal method, and applied as positive photoelectrode material of the photocatalysis-CDI system (PCS) to convert Cr(VI) to Cr(III). Active carbon was used as negative electrode material to absorb Cr(III). An enhanced removal of Cr(VI) can be obtained by applying visible light irradiation and 1.3 V direct current (DC) voltage simultaneously and the Cr(VI) removal can reach a maximum value of 81.6%, much higher than those under individual 1.3 V DC voltage (39.4%) or visible light irradiation (54.2%), demonstrating the synergistic effect from CDI and photocatalysis. More importantly, effective removal of the total Cr with high removal ratio (72.2%) can be achieved, which is difficult to be realized using current other technologies. The strategy in this work provides a promising method for the complete removal of high-valence heavy metal ions. [ABSTRACT FROM AUTHOR]

A series of MIL-53(Fe) materials was synthesized using a solvothermal method under different temperature and time conditions and were used as catalysts to activate persulfate and degrade Orange G (OG). Influences of the above conditions on the crystal structure and catalytic behavior were investigated. Degradation of OG under different conditions was evaluated, and the possible activation mechanism was speculated. The results indicate that high synthesis temperature (larger than 170 °C) leads to poor crystallinity and low catalytic activity, while MIL-53(Fe) cannot fully develop at low temperature (100 or 120 °C). The extension of synthesis time from 5 h to 3 d can increase the crystallinity of the samples, but weakened the catalytic activity, which was caused by the reduction of BET surface area and the amount of Fe (II)-coordinative unsaturated sites. Among all the samples, MIL-53(Fe)-A possesses the best crystal structure and catalytic activity. In optimal conditions, OG solution can be totally decolorized after degradation for 90 min, and a removal rate of 74% for COD was attained after 120 min. The initial solution pH had great influence on OG degradation, with the greatest removal in acidic pH environment. ESR spectra showed that sulfate radical (SO 4 − ), hydroxyl radical (OH ), persulfate radical (S 2 O 8 − ), and superoxide radical (O 2 ) exist in this system under acidic conditions. Furthermore, with the increase of pH, the relative amount of O 2 increases while that of OH and SO 4 − decreases, resulting in a reduced oxidizing capacity of the system. [ABSTRACT FROM AUTHOR]

The development of efficient materials for removing pharmaceuticals from water has been a matter of great concern. As a new class of porous materials, metal-organic frameworks (MOFs) have attracted considerable attention in the field of environmental remediation. In this article, a photocatalytic adsorbent MIL-53(Fe) was successfully prepared by solvothermal method and used for the removal of two typical pharmaceuticals clofibric acid (CA) and carbamazepine (CBZ) from water. MIL-53(Fe) exhibited good adsorption performance and the maximum adsorption capacities of CA and CBZ are about 0.80 mmol/g and 0.57 mmol/g, respectively. The adsorption mechanisms of CA and CBZ are mainly due to electrostatic interaction and π-π interaction, respectively. Further, MIL-53(Fe) exhibited high photocatalytic activity and stability under visible light. The photocatalytic efficiency could be improved significantly with the addition of a small amount of H 2 O 2 , and the corresponding photodegradation efficiencies for CA and CBZ both reached up to 90%, which are higher than those of Fe(II)/H 2 O 2 and TiO 2 under visible light. The photocatalytic performance was strongly dependent on the solution pH. The Fenton-like reaction, charge carriers directly generated in the photo-excited MIL-53(Fe) and the synergistic effect of H 2 O 2 were the main mechanisms. The formation of humic acids-like and fulvic acids-like organic matter in the degradation process was detected by 3D EMMs. MIL-53(Fe) also revealed excellent performance for the removal of CA and CBZ from real municipal wastewater and river water. Therefore, MIL-53(Fe) may be used as a promising photocatalytic adsorbent for wastewater purification. [ABSTRACT FROM AUTHOR]

As a pharmaceutical pollutant, doxycycline causes contamination when enters into the environment. In this research MIL-53(Fe), and its magnetic hybrid MIL-53(Fe)/Fe 3 O 4 were synthesized and employed for removal of doxycycline from aqueous solutions. The adsorbents were characterized by XRD, SEM, BET, FTIR, EDAX, VSM and TG-DTG technique. The effect of different variables such as DOC concentration, pH, contacting time, and adsorbent dose on the removal efficiency was studied and under optimized conditions the adsorption capacity of 322 mgg −1 was obtained. The adsorption process was kinetically fast and the equilibration was attained within 30 min. The used adsorbent was easily separated from the solution by applying external magnetic field. The regenerated adsorbent retained most of its initial capacity after six regeneration steps. The effect of ionic strength was studied and it was indicated that removal of doxycycline from salt-containing water with moderate ionic strengths was quite feasible. Langmuir, Freundlich, Tempkin and Dubinin–Redushkevich isotherms were employed to describe the nature of adsorption process. The sorption data was well interpreted by the Longmuir model. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are fascinating materials for diverse applications due to their adjustability of aperture and structure. Herein, a three-dimensional iron-based MOF with BDC linker (BDC = 1,4-benzenedicarboxylate), commonly known as MIL-53(Fe), has been synthesized and successfully composited with anionic resin (Amberlite IRA 200) and cationic resin (Amberlite IRA 900) resulting solid composite photocatalysts, AMIL-53 (Fe) and DMIL-53(Fe), respectively. In the novel composite photocatalysts, bulky MIL-53(Fe) MOF solids are used as both a support to anchor the finely ground Amberlite IRA resin powders and as a visible light active component for the degradation of organic pollutants in water. In addition to being a traditional support, the resins here were used as a co-catalyst (with loading ration of the resin to MIL-53(Fe) is controlled around 20 wt%) to capture and transfer pollutant molecule from bulk solution into the active centers of the composited catalysts. Such an immobilization of the resins significantly alters MIL-53 (Fe) activity and degradation selectivity of dye pollutants; after 120 min of visible light illumination (λ ≥ 420 nm) removal yield of SRB (24%) by the bare MIL-53 (Fe) was apparently improved to 96% after MIL-53 (Fe) was modified by Amberlite IRA 900, DMIL-53(Fe). The tunable degradation order was demonstrated by employing AMIL-53 (Fe) for the selective degradation of cationic dyes while DMIL-53 (Fe) for the degradation of anionic dyes. Furthermore, the composites activity was optimized by controlling resin to MOF ratio during immobilization. Immobilization also improves ease of separation and recyclability of the original MOF. Especially, AMIL-53 significantly reduces iron ion leaching resulting in an enhanced stability. The photocatalytic mechanism under visible-light irradiation is also discussed. [ABSTRACT FROM AUTHOR]

Various analytical applications of metal-organic frameworks (MOFs) have been rapidly developed in the past few years. However, the employment of MOFs as catalysts in chemiluminescence (CL) analysis is rare. Here, for the first time, we found that MIL-53(Fe) MOFs could significantly enhance the CL of luminol in the presence of HO in an alkaline medium. The CL intensity in the luminol-HO-MIL-53(Fe) system was about 20 times higher than that in the luminol-HO system. Moreover, the XRD pattern of MIL-53(Fe) after CL reaction was almost the same as that of the original MIL-53(Fe), confirming the catalytic role of MIL-53(Fe) in the luminol-HO-MIL-53(Fe) system. The possible mechanism behind the enhancing phenomenon was discussed based on the results from the CL spectra, FL probe experiments, and active oxygen species measurements. By coupling with the glucose oxidase-based catalytic oxidation reaction, a sensitive and selective CL method was developed for the detection of glucose. There is a linear relationship between the logarithm of CL intensity and the logarithm of glucose concentration in the range from 0.1 to 10 μM, and a detection limit of 0.05 μM (S/N = 3) is obtained. The proposed method has been applied to the determination of glucose in human serum samples with satisfactory results. [ABSTRACT FROM AUTHOR]

A series of MIL-53(Fe)-graphene nanocomposite photocatalysts were synthesized by a facile one-pot solvothermal reaction. All materials have been thoroughly characterized by FT-IR, SEM, TEM, PXRD, UV–vis DRS and PL analysis. It was demonstrated that the introducing of graphene on the MIL-53(Fe) would minimize the recombination of photogenerated electron-hole pairs, thus, leading to the enhancement of photocatalytic activity. MIL-53(Fe)-graphene nanocomposite was an efficient catalyst towards the photocatalytic selectively oxidation of alcohols to the corresponding aldehydes or ketones under visible light and ambient conditions. High selectivity of the aldehydes or ketones (99%) were obtained. Meanwhile, the catalyst can be recycled at least four times without loss of catalytic efficiency. A possible photocatalytic reaction mechanism involving a direct photogenerated hole-oxidation process was also investigated in detail by the active species trapping experiments and the related electrochemical analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • MIL-53(Fe) was immobilized into the PVDF to obtain mixed-matrix membranes. • MIL-53(Fe)/PVDF was integrated into the photocatalytic membrane reactor to remove tetracycline. • Removal of tetracycline was enhanced by the combination of separation and catalysis mechanisms. • Over 99.0 % of tetracycline was removed by the photocatalytic membrane reactor. • Tetracycline was degraded by h+ and •OH radicals. This work demonstrates the synergistic effect of two-unit operations: filtration and photocatalysis to remove tetracycline (TC) from wastewater by immobilizing MIL-53(Fe) photocatalyst into the poly (vinylidene fluoride) (PVDF) matrix to create a mixed-matrix membrane (MMM) in a photocatalytic membrane reactor (PMR). Herein, 1.0–5.0 wt% of MIL-53(Fe) was blended into a PVDF-based casting solution to obtain MMMs after phase-inversion. The addition of MIL-53(Fe) resulted in an increased viscosity of the casting solution which caused the macrovoids decorating the cross-section of the polymer matrix to be suppressed, consequently decreasing the bulk pore size from 0.06 to 0.014 µm. Moreover, it also increased the bulk tortuosity by suppressing the macrovoid formation which enhanced the depth-filtration mechanism of the modified membranes, particularly P10M5 which delivered the highest rejection of 87 % against TC. Meanwhile, LC/MS technique confirmed the degradation of TC under UV illumination and revealed that P10M5 provided optimal condition for degrading TC with 93 % degradation efficiency. The trapping experiments revealed that the dominating reactive oxidation species responsible during the degradation process were h+ and •OH species. Our results indicate that TC was photocatalytically degraded through a series of de-amidation, de-hydroxymethylation, and ring opening reactions. Through the integration of size-exclusion/depth-filtration mechanisms offered by the membrane, and degradation process provided by MIL-53(Fe), the PMR system using P10M5 successfully removed tetracycline in the permeate and < 1 % undegraded TC remained. The findings of this study offer a viable approach to solve the crises of pharmaceutical products in wastewater by simultaneously rejecting and degrading these compounds. [ABSTRACT FROM AUTHOR]

• Millimeter-size polymer anchored MIL-53(Fe)@polyethersulfone balls were validated for elimination of carbamazepine. • Improved photocatalytic performance of MIL-53(Fe) by 4 times through the chelation of Polyethersulfone. • the composite balls can be recovered by simple precipitation and filtration method. Fe-MOFs are expected to be the candidates for heterogeneous Fenton catalysts due to their porous channel and high specific surface area feature. However because of their small size they are difficult to recycle, and the low Fe(II) concentration make them low efficiency for H 2 O 2 activation. Herein, we report millimeter-scale polymer anchored porous MIL-53(Fe) composite balls with highly improved Fenton-like performance and easy recycling for the elimination of carbamazepine. It is prepared via MIL-polyethersulfone dope and solvent/water exchange method with organic ligand substitution strategy that affording S O and C O mixed-coordination. The degradation rate constant for MIL-53(Fe)@PES is 4 times that of pure MIL-53(Fe), while the degradation rate constant of photo Fenton is 79 times of dark one. The composite balls can be recovered by simple precipitation process and the removal efficiency of carbamazepine still reach 80% after 5 cycles of regeneration. The mechanism of photo-Fenton degradation of carbamazepine were proposed. [ABSTRACT FROM AUTHOR]

In the last decade, Metal-organic frameworks (MOFs) were utilized to uptake pollutants from water due to their distinctive features such as tunability, high surface area, and ease of functionalization. In the present research, a novel amine-functionalized MIL-DETA-n (n ​= ​DETA molar ratio) was prepared through the impregnation method using diethylenetriamine (DETA) and MIL-53 (Fe) and characterized using SEM, EDX, XRD, FT-IR, and BET analyses. The MIL-DETA-n was used to adsorb As(V) from aqueous media, and adsorption capacity was reached 137.5 ​mg/g. DETA functionalization of MIL-53(Fe) decreased Fe leaching and kept Fe concentration below 0.3 ​mg/L as the maximum contaminant level. The effect of different parameters such as temperature, pH, trace arsenate concentrations, co-existing ions, and reusability was studied. The kinetic and thermodynamic studies demonstrated that adsorption follows the pseudo-second-order model, and the equilibrium data fits with the Langmuir isotherm. For the first time, the MIL-DETA-n was successfully employed to remove arsenic from surfaces and groundwater. [Display omitted] • Successfully amine-functionalization of MIL-53(Fe) using diethylenetriamine to prepare MIL-DETA. • High performance of MIL-DETA adsorbent to uptake As(V). • Reaching arsenate removal capacity to 137.5 ​mg/g. • Decrease in Fe leaching after amine-functionalization. • The superior efficiency of MIL-DETA in polluted surfaces and groundwater. [ABSTRACT FROM AUTHOR]

The biocompatible MIL-53(Fe) was synthesized and utilized to load Ag ions via a simple impregnation resulting in an antibacterial system Ag@MIL-53(Fe). The materials were characterized by PXRD and SEM. The loading capacity and antibacterial performance of powders at different mass ratio were further investigated. The Ag ions content of Ag@MIL-53(Fe) reached to maximum (about 40.62 ​wt%) at the mass ratio of 1:1 which was measured by ICP. The inhibition zone radius of material (Ag 40.62 ​wt%) showed the optimal efficiency against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) while MIL-53(Fe) demonstrated negligible antimicrobial performance. The excellent antibacterial activity and desirable biocompatibility of Ag@MIL-53(Fe) implied its promising prospect in antibacterial. Ag ions as a typical antibacterial agent was loaded into MIL-53(Fe) via a simple impregnation method resulting in an antibacterial system Ag@MIL-53(Fe). MIL-53(Fe) exhibited the poor inhibition of S. aureus and E. coli while the obvious inhibition zone of Ag@MIL-53(Fe) was observed, the phenomena implied the excellent antibacterial behaviors of Ag@MIL-53(Fe) against both S. aureus and E. coli. [Display omitted] • A biocompatible MOF MIL-53(Fe) was synthesized. • Ag ions was loaded into MIL-53(Fe) to construct an antibacterial system Ag@MIL-53(Fe). • Ag@MIL-53(Fe) (Ag 40.62 wt%) showed optimal efficiency against both S. aureus and E. coli. [ABSTRACT FROM AUTHOR]

• The photo-Fenton catalyst MIL-53(Fe)/BiOI were prepared by co-precipitation method. • MIL-53(Fe)/BiOI can effectively degrade tetracycline in mild pH. • The enhanced degradation ability depends on the synergy of photocatalysis and Fenton. • Singlet oxygen and hole were demonstrated to be the main active species. • The possible reaction pathway and mechanism diagram were proposed. [Display omitted] In this work, a series of MIL-53(Fe)/BiOI composites were synthesized by a combined hydrothermal and facile co-precipitation method. The heterojunctions were further used as photocatalysts for tetracycline (TC) degradation in photo-Fenton system. The TC degradation rate constant for MIL-53(Fe)/BiOI (0.0906 min−1) was 2.1 and 2.3 times higher than that for MIL-53(Fe) (0.0432 min−1) and BiOI (0.0389 min−1), respectively. The photoelectrical characterization results suggested that the enhanced photocatalytic activity of the MIL-53(Fe)/BiOI composite was attributed to the high electron and holes separation efficiency. The scavenging experiment results and electron spin resonance analysis demonstrated that h+ and singlet oxygen were the main reactive species in the degradation process. The possible photo-Fenton degradation mechanism was further elucidated based on the band structures of MIL-53(Fe) and BiOI with the generation process of reactive species. This work provided a new idea to construct metal-organic-framework-based composite photocatalysts for photo-Fenton system, and it is also promising for the applications in environmental restoration and protection field. [ABSTRACT FROM AUTHOR]

• Successful development of novel low-crystalline bimetallic MOFs as excellent photo-Fenton catalysts. • Achievement of intensified synergism between hetero-metal nodes in the low-crystalline bimetallic MOFs. • Low-crystalline state, further strengthened the role of doped metal. • The electron-rich Fe sites were formed in the low-crystalline MOFs. • Low-crystalline MOFs enable exposure of more metal CUSs, beneficial for H 2 O 2 coordination. In this study, the low-crystalline bimetallic metal-organic frameworks (MOFs) of L-MIL-53(Fe, Mn) and L-MIL-53(Fe, Cu) (MIL: Material of Institute Lavoisier) were successfully developed as photo-Fenton catalysts, exhibiting significantly enhanced degradation performance (15.2 and 2.49 times increase in reaction rate constant, respectively) for ciprofloxacin (CIP) in contrast to their crystalline counterparts. That were mainly attributed to the intensified synergism between hetero-metal nodes. Specifically, taking L-MIL-53(Fe, Mn) as an example, the formed electron-rich Fe sites along with the strengthened roles of Mn for enlarged specific surface area, enhanced visible-light absorption and separation and transportation of photo-induced carriers in the low-crystalline state, are responsible for acceleration of Fe(II)/Fe(III) and Mn(II)/Mn(III) cycles, beneficial for H 2 O 2 activation. Moreover, increased metal coordinately unsaturated sites (CUSs) are favorable for more H 2 O 2 coordination. This work gives a deep insight into the heterogeneous photo-Fenton mechanism of the bimetallic MOFs in their low-crystalline state. [ABSTRACT FROM AUTHOR]

MIL-53(Fe) is a metal organic framework that has been recently considered a heterogeneous photocatalyst candidate for the degradation of water pollutants under visible or solar radiation, though stability studies are rather scarce in the literature. In this work, MIL-53(Fe) was successfully synthesized by a solvothermal method and fully characterized by X-ray diffraction (XRD), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), N2 adsorption–desorption isotherm, Thermogravimetric analysis coupled with mass spectrometry (TGA-MS), UV-visible diffuse reflectance spectroscopy (DRS), elemental analysis and wavelength dispersive X-ray fluorescence (WDXRF). The effects of pH, temperature, solar radiation and the presence of oxidants (i.e., electron acceptors) such as ozone, persulfate and hydrogen peroxide on the stability of MIL-53(Fe) in water were investigated. The as-synthetized MIL-53(Fe) exhibited relatively good stability in water at pH 4 but suffered fast hydrolysis at alkaline conditions. At pH 4–5, temperature, radiation (solar and visible radiation) and oxidants exerted negative effect on the stability of the metal–organic framework (MOF) in water, resulting in non-negligible amounts of metal (iron) and linker (terephthalic acid, H2BDC) leached out from MIL-53(Fe). The photocatalytic activity of MIL-53(Fe) under simulated solar radiation was studied using phenol and metoprolol as target pollutants. MIL-53(Fe) on its own removed less than 10% of the pollutants after 3 h of irradiation, while in the presence of ozone, persulfate or hydrogen peroxide, complete elimination of pollutants was achieved within 2 h of exposure to radiation. However, the presence of oxidants and the formation of some reaction intermediates (e.g., short-chain carboxylic acids) accelerated MIL-53(Fe) decarboxylation. The findings of this work suggest that MIL-53(Fe) should not be recommended as a heterogeneous photocatalyst for water treatment before carrying out a careful evaluation of its stability under actual reaction conditions. [ABSTRACT FROM AUTHOR]

This work highlights a systematic investigation on doping (S2−) on photoactive MIL-53(Fe) and its performance evaluation. Doping (structural/interstitial), leading to tailoring of optical band-gap energies of the parent materials to maximize their performances is well known. However, alteration or tuning of band-gap energy may not essentially always lead to a better performance in photocatalytic reactions and this aspect becomes more pertinent for hybrid materials like Metal Organic Frameworks (MOFs). Since, doping might lead to wider variations in structural conformations in a hybrid MOF like material, underlines the importance of the extent. A microwave synthesis route was proposed to effectively synthesize the products where dopant (S2−) percentages were varied from 1 to 10% stoichiometrically in the reaction mixture. Different spectroscopic techniques like UV–vis DRS, FT-IR, micro Raman, Photoluminescence (PL), Electrochemical Impedance Spectroscopy (EIS) and Electron Spin Resonance spectroscopy (ESR) were used to understand the extent of doping on structural conformations of MIL-53(Fe). The influence of doping showed an increase in optical-band gap energy w.r.t to parent MIL-53(Fe) (1.996 eV): 1% S (2.224 eV); 4% S (2.376 eV), 7% S (2.448 eV) and 10% S (2.579 eV). The coordination of metal oxo cluster from calculated Nephelauxetic factor values in synthesized materials showed electron cloud expansion from 6.51% (1% S) to 16.36% (10% S). The IVCT band intensity was highest for 1%S and accordingly Methylene blue (MB) degradation yielded best performance for 1%S doped MIL-53(Fe) (ca. 97.14%) and repeatability study showed the material to be stable even after 5 cycles. The overall reaction mechanism was hypothesized based on DPBF assay and standard reaction kinetic trap analyses. Image 1 • Successfully synthesized novel S2− doped MIL-53(Fe) using facile microwave route. • An increase in dopant percentage (S2−), increased the optical band gap energy of the photoactive materials. • 1% S2− doped MIL-53(Fe) showed the best photodegradation of MB dye (ca. 97.14%), 4.32 time more than parent MIL-53(Fe). • Recyclability study showed synthesized material remained active even after 5 cycles of degradation experiment. • Higher doping percentage was found to be detrimental in terms of photoactivity. [ABSTRACT FROM AUTHOR]

Series MIL-53(Fe)/Bi 12 O 17 Cl 2 (MB x) composites were constructed via facile ball-milling treatment of the MIL-53(Fe) octahedrons and Bi 12 O 17 Cl 2 nanosheets. The addition of a specific quality of Bi 12 O 17 Cl 2 was in favor of strengthening the transfer ability of photo-generated charge carriers in the composites, thereby further enhancing the photocatalytic performance. Being compared with pristine MIL-53(Fe) and Bi 12 O 17 Cl 2 , the MB x composites exhibited superior white-light-driven Cr(VI) photoreduction performance. The optimal MB100 photocatalyst displayed the best photocatalytic activity, in which 99.2% Cr(VI) can be eliminated within 90 min under white light illumination. Under the identical reaction conditions, it achieved 42.9% and 76.5% higher improvements as those of pure MIL-53(Fe) and Bi 12 O 17 Cl 2. More than that, the MB100 also demonstrated good stability even after four cycles of testing experiments. At last, the corresponding reaction mechanism was clarified based on the electrochemical analysis and electron spin resonance (ESR) data. Such heterogeneous photocatalyst design strategy based on Fe-MOFs and bismuth-rich bismuth oxyhalides might provide new insights for treating Cr-containing wastewater. MIL-53(Fe)/Bi 12 O 17 Cl 2 (MB x) composites constructed by ball-milling method exhibit remarkable photocatalytic activities toward Cr(VI) reduction. Image 1 • MIL-53(Fe)/Bi 12 O 17 Cl 2 (MB x) composites were constructed by ball-milling method. • The composites exhibited good Cr(VI) photoreduction performances under white light. • Z-scheme mechanism of Cr(VI) photoreduction over MB100 was put forward in this study. [ABSTRACT FROM AUTHOR]

In this research, cobalt ferrite (CoFe 2 O 4) magnetic nanoparticles as well as MIL-53(Fe) structure were synthesized by the hydrothermal and solvothermal methods, respectively. Moreover, magnetic composites of MIL-53(Fe)/CoFe 2 O 4 nanoparticles with different cobalt ferrite loadings (i.e.; 0.05, 0.1 and 0.2 g) were prepared via the solvothermal method. The main novelty of the present research was to synthesize a magnetic composite of MIL-53(Fe)/CoFe 2 O 4 nanoparticles in order to perform rapid photodegradation of Direct Red 23 (DR23) dye under the LED visible light irradiation. Good magnetic properties of the fabricated composite led to easy separation and rapid retrieval of the catalyst from the reaction mixture. Effects of operational variables such as the initial dye concentration, photocatalyst loading and solution pH upon the performance of synthesized materials were understudied. Characterizations of the prepared photocatalysts were performed through the XRD, SEM, TEM, EDX, FTIR, as well as VSM, DRS, BET-BJH and EIS analyses. Results of the XRD, SEM and FTIR analyses confirmed successful synthesis of CoFe 2 O 4 , MIL-53(Fe) and their magnetic composites. Moreover, the desired magnetic value of 28.5 emu/g at 8128 Oe was determined for the MIL-53(Fe)/0.1gCoFe 2 O 4 material. Furthermore, the highest light absorption intensity by this composite was obtained through the UV–Visible DRS analysis. In addition, the value of optical bandgap energy (E g) for the aforementioned composite was determined to be 2.1 eV. Furthermore, the BET surface areas of the MIL-53(Fe), MIL-53(Fe)/0.1gCoFe 2 O 4 and CoFe 2 O 4 species were evaluated to be 13, 34 and 52 m2/g, respectively. Finally, the photocatalytic degradation of the DR23 over the MIL-53(Fe)/0.1gCoFe 2 O 4 was revealed to be 99.35% after 80 min of duration under the LED irradiations. This was higher than the rest of other understudied materials. In addition, results displayed that, the hydroxyl radicals (OH) as well as photo-generated holes (h+) were the main active species in photocatalytic degradation process undertaken. Ultimately, sufficient yet simple rate law models of the aforementioned dye degradation implementing first- and second-order chemical kinetics upon the prepared catalysts were developed. Unlabelled Image • The synthesized magnetic MIL-53(Fe)/CoFe 2 O 4 led to 99.35% dye degradation. • Effects of pH, C o,DR23 and catalyst loading on photocatalyst activity were studied. • Magnetic behaviour caused easy separation and retrieval of the used photocatalyst. • Optimum loading of CoFe 2 O 4 for magnetic composites was determined to be 0.1 g. • Kinetic models of photocatalytic DR23degradation by various catalysts were studied. [ABSTRACT FROM AUTHOR]

The impurity of salicylic acid (SA) in aspirin is a required inspection item for drug quality control. Since free SA is significantly toxic for humans, the content determination of free SA is absolutely necessary to ensure people's health. In this work, a facile colorimetric method was developed for the detection of SA in aspirin by utilizing the MIL-53(Fe) nanozyme. As MIL-53(Fe) possesses enzyme mimicking catalytic activity, 3,3,5,5-tetramethylbenzidine (TMB) can be easily oxidized to blue-oxidized TMB (oxTMB) with the existence of H 2 O 2 . Moreover, an inhibition effect on the catalytic activity of the MIL-53(Fe) nanozyme is induced due to the specific complexation between SA and Fe 3+ in the center of MIL-53(Fe), which results in a lighter color in the oxTMB. The color change of oxTMB can be seen easily by the naked eye with the addition of different concentrations of SA. Thus, a simple colorimetric platform was established for effectively monitoring SA. A good linear relationship ( R 2 = 0.9990) was obtained in the concentration range of 0.4-28 μmol L -1 , and the detection limit was 0.26 μmol L -1 . In particular, the rationally designed system has been well-applied to the detection of SA impurity in aspirin. Satisfyingly, the detection results are highly in accord with those of HPLC. This novel colorimetric platform broadens the application prospects of nanozymes in the field of pharmaceutical analysis., (Copyright © 2020 Liang, Huang, Liu, Zuo, Ye and Zhao.)

This study describes the preparation and characterisation of MIL-53(Fe) and its effect on the performance of forward osmosis (FO) membranes. The cellulose acetate (CA)/MIL-53(Fe) hybrid membranes were fabricated using the method of phase inversion by dispersing MIL-53(Fe) in a CA casting solution. To improve the selectivity and permeability performance of FO membranes, the effects of MIL-53(Fe) content, casting solution temperature, coagulation bath temperature, and annealing temperature were studied. Results from scanning electron microscopy, membrane porosity, atomic force microscopy, and water contact angle tests of all the membranes show that the structural properties of the CA/MIL-53(Fe) hybrid membranes were optimised. The results of the FO performance tests, including the values of water flux and reverse salt flux, indicate improvement in the selectivity and permeability properties of the CA/MIL-53(Fe) hybrid membranes. Under the conditions of deionised water as the feed solution and 1 M NaCl solution as the draw solution, the water flux and reverse salt flux of the CA/MIL-53(Fe) hybrid membranes reached 34.9 L/(m2·h) and 2.02 g/(m2·h), respectively, in comparison with CA membranes. This study demonstrates that MIL-53(Fe) can improve the desalination performance and structural properties of FO membranes. • MIL-53(Fe) with high porosity was used to fabricate cellulose acetate (CA)/MIL-53(Fe) hybrid membranes for the first time. • Optimal experimental conditions of CA/MIL-53(Fe) hybrid membranes were conducted. • The water flux and reverse salt flux of CA/MIL-53(Fe) hybrid membranes were improved compared to CA membranes. • Effect of MIL-53(Fe) on structural properties of CA membranes was widely discussed. [ABSTRACT FROM AUTHOR]

Mixed Ni/Fe-base metal-organic framework (Ni/Fe-MOF) with different molar ratios of Ni2+/Fe3+ have been successfully produced using an appropriate solvothermal router. Physicochemical properties of all samples were characterized using X-ray diffraction (XRD), Raman, field emission scanning electron microscopes (FE-SEM), fourier-transform infrared spectroscopy (FT-IR), N2 adsorption-desorption analysis, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS), and photoluminescence spectra (PL). The photocatalytic degradation performances of the photocatalysts were evaluated in the decomposition of rhodamine B (RhB) under a compact fluorescent daylight lamp. From XRD, IR, XPS, and Raman results, with the presence of mixed ion Fe3+ and Ni2+, MIL-88B (MIL standing for Materials of Institut Lavoisier) crystals based on the mixed metal Fe2NiO cluster were formed, while MIL-53(Fe) was formed with the presence of single ion Fe3+. From UV-Vis DRS results, Ni/Fe-MOF samples exhibited the absorption spectrum up to the visible region, and then they showed the high photocatalytic activity under visible light irradiation. A Ni/Fe-MOF sample with a Ni2+/Fe3+ molar ratio of 0.3 showed the highest photocatalytic degradation capacity of RhB, superior to that of the MIL-53(Fe) sample. The obtained result could be explained as a consequence of the large surface area with large pore volumes and pore size by the Ni2+ incorporating into the MOF's structure. In addition, a mixed metal Fe/Ni-based framework consisted of mixed-metal cluster Fe2NiO with an electron transfer effect and may enhance the photocatalytic performance. [ABSTRACT FROM AUTHOR]