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This study introduces recommendations for conducting molecular simulations of vapor adsorption, with an emphasis on enhancing the accuracy, reproducibility, and comparability of results. The first aspect we address is consistency in the implementation of some details of typical molecular models, including tail corrections and cutoff distances, due to their significant influence on generated data. We highlight the importance of explicitly calculating the saturation pressures at relevant temperatures using methods such as Gibbs ensemble Monte Carlo simulations and illustrate some pitfalls in extrapolating saturation pressures using this method. For grand canonical Monte Carlo (GCMC) simulations, the input fugacity is usually calculated using an equation of state, which often requires the critical parameters of the fluid. We show the importance of using critical parameters derived from the simulation with the same model to ensure internal consistency between the simulated explicit adsorbate phase and the implicit bulk phase in GCMC. We show the advantages of presenting isotherms on a relative pressure scale to facilitate easier comparison among models and with experiment. Extending these guidelines to a practical case study, we evaluate the performance of various isoreticular metal–organic frameworks (MOFs) in adsorption cooling applications. This includes examining the advantages of using propane and isobutane as working fluids and identifying MOFs with a superior performance. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs), with their unique porous structures and versatile functionality, have emerged as promising materials for the adsorption, separation, and storage of diverse molecular species. In this study, we investigate water adsorption in MOF-808, a prototypical MOF that shares the same secondary building unit (SBU) as UiO-66, and elucidate how differences in topology and connectivity between the two MOFs influence the adsorption mechanism. To this end, molecular dynamics simulations were performed to calculate several thermodynamic and dynamical properties of water in MOF-808 as a function of relative humidity (RH), from the initial adsorption step to full pore filling. At low RH, the μ3-OH groups of the SBUs form hydrogen bonds with the initial water molecules entering the pores, which triggers the filling of these pores before the μ3-OH groups in other pores become engaged in hydrogen bonding with water molecules. Our analyses indicate that the pores of MOF-808 become filled by water sequentially as the RH increases. A similar mechanism has been reported for water adsorption in UiO-66. Despite this similarity, our study highlights distinct thermodynamic properties and framework characteristics that influence the adsorption process differently in MOF-808 and UiO-66. [ABSTRACT FROM AUTHOR]

Hydrofluorocarbons (HFCs) have important applications in different industries; however, they are environmentally unfriendly due to their high global warming potential (GWP). Hence, reclamation of used hydrofluorocarbons via energy-efficient adsorption-based separation will greatly contribute to reducing their impact on the environment. In particular, the separation of azeotropic refrigerants remains challenging, such as typical mixtures of CH2F2 (HFC-23) and CHF3 (HFC-32), due to a lack of adsorptive mechanisms. Metal–organic frameworks (MOFs) can provide a promising solution for the separation of CHF3–CH2F2 mixtures. In this study, the adsorption mechanism of CHF3–CH2F2 mixtures in TIFSIX-2-Cu-i was revealed at the microscopic level by combining static pure-component adsorption experiments, molecular simulations, and density-functional theory (DFT) calculations. The adsorption separation selectivity of CH2F2/CHF3 in TIFSIX-2-Cu-i is 3.17 at 3 bar under 308 K. The existence of similar TiF62− binding sites for CH2F2 or CHF3 was revealed in TIFSIX-2-Cu-i. Interactions between the fluorine atom of the framework and the hydrogen atom of the guest molecule were found to be responsible for determining the high adsorption separation selectivity of CH2F2/CHF3. This exploration is important for the design of highly selective adsorbents for the separation of azeotropic refrigerants. [ABSTRACT FROM AUTHOR]

H2O2 production by photocatalysis has received considerable attention, while using MOF‐based materials as photocatalysts is still less explored. Ligand functionalization of MOFs is a decoration way at the molecular level, which provides the basis for the further modification of MOFs. In this concept, ligand functionalization of MOFs for photocatalytic H2O2 production has been systematically and extensively discussed. The strategies of ligand functionalization include grafting of functional groups (e. g. amino, methoxyl, boron and alkyl) and multiple ligand decoration. Correspondingly, some specific effects are achieved, e. g. improved charge carrier separation, enhanced O2 adsorption and hydrophobicity, which can realize efficient H2O2 production by photocatalysis. Meanwhile, reaction conditions and activities of photocatalytic H2O2 production have also been explicitly introduced in these studies. At last, the future perspectives are proposed. This concept sheds fresh light on the great potential of ligand functionalization of MOFs for photocatalytic H2O2 production. [ABSTRACT FROM AUTHOR]

Core–Shell structured microspheres with a packed nano‐platelet copper hydroxysulfate (CHS) core and an octahedral crystalized metal–organic framework‐199 (CHS@M199) shell are synthesized and tested as adsorbent for gaseous formaldehyde (FA). CHS@M199 outperforms reference materials (e.g., activated carbon (AC), CHS, and M199) with adsorption capacity (Q) of 8.13 mg g−1 and partition coefficient (PC) of 0.263 mol kg−1 Pa−1 against 10 Pa FA at 10% breakthrough (BT) level with the aid of large surface area and copper sites for coordinating with carbonyl group. Contrary to general expectations, CHS@M199 exhibits a unique adsorption behavior in that BT volume increases systematically with the rise in FA inlet partial pressure (e.g., 5–10 Pa). The 10% BT capacity of CHS@M199 decreases noticeably (8.13 to 2.08 mg g−1) with increasing relative humidity (0.016 to 10%), reflecting water‐FA competition for hydrophilic adsorption sites. Although FA adsorption on CHS@M199 diminishes with elevated RH levels, such reduction intensifies when simulating ambient conditions (through stepwise addition of competing components: O2, CO2, and H2O). The FA adsorption on CHS@M199 is well described by both pseudo‐first‐order (PFO) and pseudo‐second‐order (PSO) kinetics. Polymerization may play a pivotal role in the adsorption of FA on CHS@M199, as Qi‐LeVan isotherm best fits the experimental data. [ABSTRACT FROM AUTHOR]

The green water‐based adsorption refrigeration is considered as a promising strategy to realize near‐zero‐carbon cooling applications. Although many metal‐organic frameworks (MOFs) have been developed as water adsorbents, their cooling performance are commonly limited by the insufficient water uptakes below P/P0 = 0.2. Herein, the development of multivariate MOFs (MTV‐MOFs) is reported to highly modulate and boost the low‐pressure water uptake for improving coefficient of performance (COP) for refrigeration. Through ligand exchange in the pristine MIL‐125‐NH2, a series of MTV‐MOFs with bare nitrogen sites are designed and synthesized. The resulting MIL‐125‐NH2/MD‐5% exhibits the significantly improved water uptake of 0.39 g g−1 at 298 K and P/P0 = 0.2, which is three times higher than MIL‐125‐NH2 (0.12 g g−1) and comparable to some benchmark materials including KMF‐1 (0.4 g g−1) and MIP‐200 (0.36 g g−1). Combined with its low‐temperature regeneration, fast sorption kinetics and high stability, MIL‐125‐NH2/MD‐5% achieves one of the highest COP values (0.8) and working capacities (0.24 g g−1) for refrig‐2 under an ultralow‐driven temperature of 65 °C, which are higher than some best‐performing MOFs such as MIP‐200 (0.74 and 0.11 g g−1) and KMF‐2 (0.62 and 0.16 g g−1), making it among the best adsorbents for efficient ultralow‐temperature‐driven refrigeration. [ABSTRACT FROM AUTHOR]

Angular ligands are a class of important linkers to design and construct new metal–organic frameworks (MOFs). Herein, solvothermal reaction of 4,4′-(4H-1,2,4-triazole-3,5-diyl)dibenzoic acid (TZDB), a triazole-inserted dicarboxylate, acetate, and Cu(NO3)2·3H2O afforded a copper(II)-organic framework of Cu-TZDB. Structural analysis shows that Cu-TZDB displays an unusual (4,6)-c topological network concomitant with the generation of metalloligand [Cu(TZDB)(H2O)2] in situ. Due to its bi-channel cavities replete with triazolate, coordinated water and methyl groups, Cu-TZDB exhibits CO2 selective adsorption over N2 and CH4, which was not only predicted by ideal adsorption solution theory (IAST), but also verified by dynamic column breakthrough tests. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are superior ion adsorbents for selectively capturing toxic ions from water. Nevertheless, they have rarely been reported to have lithium selectivity over divalent cations due to the well-known flexibility of MOF framework and the similar physiochemical properties of Li+ and Mg2+. Herein, we report an ion-sieving adsorption approach to design sunlight-regenerable lithium adsorbents by subnanoporous MOFs for efficient lithium extraction. By integrating the ion-sieving agent of MOFs with light-responsive adsorption sites of polyspiropyran (PSP), the ion-sieving adsorption behaviors of PSP-MOFs with 6.0, 8.5, and 10.0 Å windows are inversely proportional to their pore size. The synthesized PSP-UiO-66 with a narrowest window size of 6.0 Å shows high LiCl adsorption capacity up to 10.17 mmol g−1 and good Li+ / Mg2+ selectivity of 5.8 to 29 in synthetic brines with Mg/Li ratio of 1 to 0.1. It could be quickly regenerated by sunlight irradiation in 6 min with excellent cycling performance of 99% after five cycles. This work sheds light on designing selective adsorbents using responsive subnanoporous materials for environmentally friendly and energy-efficient ion separation and purification. [ABSTRACT FROM AUTHOR]

This manuscript is reporting hydrogen adsorption uptake of PCN‐250(Fe) metal organic framework (MOF) at temperature of 300, 126K, and pressure in between 6 and 10 bar. X‐ray diffraction spectrum of PCN‐250(Fe) confirms crystalline structure, however Fourier transform infrared (FT‐IR) spectrum showing dominant bonding structure of COOH, N = N, and Fe─O functional groups. SEM images confirm surface morphology as an octahedrons of average crystalline size upto 50 µm. Thermogravimetric analysis (TGA) confirms excellent thermal stability upto 450 °C. The hydrogen adsorption uptake of 0.80 wt% has been found at 126 K and pressure of 10 bar attributes adsorption occurs due to the structural and physical properties like topology, porosity, and presence of open metal sites as well as surface area. It is suggested that PCN‐250(Fe) as an adsorbent material offers as an intensive way of storing H2 at low temperature and at ambient pressure. [ABSTRACT FROM AUTHOR]

The flue gas produced by fossil fuel combustion contains a large amount of CO 2 , and the greenhouse effect caused by CO 2 emissions is becoming increasingly serious. There is an urgent need to develop adsorbents with excellent CO 2 adsorption performance. In this study, a new composite graphene oxide (GO) -metal-organic framework (MOF) (UiO-66-(OH) 2 /GO) was synthesized using UiO-66-(OH) 2 as a precursor. Structural analysis of the parent materials and composites found that pore structures and Brunauer–Emmett–Teller (BET) surface area could be adjusted by adding GO, and GO was tested as a carbon dioxide adsorbent at 273 K and 298 K. The maximum CO 2 adsorption of the composites was 5.03 mmol/g and 4.34 mmol/g, which was 36.7% and 36.9% higher than that of the parent materials at 1 bar, respectively. Dynamic breakthrough experiments were used to study the CO 2 /N 2 separation capability of the composites. The stability of composites was studied by chemical stability experiments and several adsorption/desorption experiments. The results showed that the composites had good acid resistance and cycle stability. The separation performance of CO 2 /N 2 in the presence of water vapor was investigated, and the composites showed good water stability. Therefore, UiO-66-(OH) 2 /GO has latent applications in CO 2 capture technology to mitigate global warming. [ABSTRACT FROM AUTHOR]

Fluoride is one of the drinking water contaminants regulated by the World Health Organization. The reduction of fluoride concentration to a safe range is of paramount importance to human life. Moreover, the fast and high-capacity removal of radioactive 18F wastes is still challenging. Metal organic frameworks (MOFs) are a hybrid class of materials that can diminish such contaminants via both adsorption and catalysis processes. In this work, we synthesize three different MOFs and study their adsorption behavior towards fluoride ion removal. The synthesized materials were characterized using X-ray diffraction, FT-IR and scanning electron microscopy. Following investigation we showed that the assynthetized materials were highly stable and had significantly effective fluoride adsorption performance What is more, the activity of fluoride captured by the material Al-Fu MOF is 603 µCi in 40 mg of this material, i.e., the removal efficiency is about 98%. [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]

Hierarchically porous metal–organic frameworks (HP-MOFs) possess the advantages of the high porosity of MOFs and unique properties, such as a wide pore size range. Hierarchically porous ZIF-8 (HP-ZIF-8) was facilely fabricated via a one-step method in supercritical CO2 (scCO2) using a competitive ligand. The mesoporous structure and morphology of HP-ZIF-8 can be easily adjusted by changing the dosage of competing ligands and the reaction temperature. When the molar ratio of zinc acetylacetonate, 2-methylimidazole, and 2-butyl-1H-imidazole was 1 : 1 : 6, the HP-ZIF-8 with micropores (1.7 nm) and mesopores (3.9–30 nm) was synthesized at 50 °C and 30 MPa for 3 hours with excellent reproducibility. The as-synthesized ZIF-8 shows a high activity for CO2 adsorption, and the CO2 equilibrium adsorption capacity reached up to 1.49 mmol g−1 sorbent at 25 °C and 0.1 MPa. Moreover, the CO2 equilibrium adsorption capacity of HP-ZIF-8 was maintained at 1.36 mmol g−1 sorbent after 7 cycles. [ABSTRACT FROM AUTHOR]

MFM‐520(Zn) confines dimers of NO2 with a high adsorption of 4.52 mmol g−1 at 1 bar at 298 K. The synthesis and the incommensurate structure of Cu‐doped MFM‐520(Zn) are reported. The introduction of paramagnetic Cu2+ sites allows investigation of the electronic and geometric structure of metal site by in situ electron paramagnetic resonance (EPR) spectroscopy upon adsorption of NO2. By combining continuous wave and electron‐nuclear double resonance spectroscopy, an unusual reverse Berry distorted coordination geometry of the Cu2+ centers is observed. Interestingly, Cu‐doped MFM‐520(Zn0.95Cu0.05) shows enhanced adsorption of NO2 of 5.02 mmol g−1 at 1 bar at 298 K. Whereas MFM‐520(Zn) confines adsorbed NO2 as N2O4, the presence of monomeric NO2 at low temperature suggests that doping with Cu2+ centers into the framework plays an important role in tuning the dimerization of NO2 molecules in the pore via the formation of specific host‐guest interactions. [ABSTRACT FROM AUTHOR]

Schematic diagram of the toluene removal by UiO-66 (Zr). [Display omitted] • The unexpected efficient toluene removal by UiO-66 under visible light was studied. • DFT showed that toluene was preferentially adsorbed on the metal center Zr. • The heating-induced adsorption of UiO-66 to toluene was firstly revealed. • Charge transfer between UiO-66 and adsorbed toluene extended the carrier lifetime. • Synergic effect of heating-induced adsorption and photodegradation was proposed. The removal of indoor/outdoor toluene by photocatalysis has drawn much attention due to its low energy consumption and easy availability. However, light inevitably generates heat, and pollutants desorb from catalysts as the temperature rises, which is not beneficial to degradation. Contrast to the frequently occurred phenomena, we firstly found that the adsorption capacity of UiO-66 (Zr) on toluene increased with increasing temperature as adsorption isotherms and in-situ Fourier transform infrared spectra (in-situ FTIR) showed. The optimum temperature was 30 °C. This stage in which adsorption capacity was positively correlated with temperature was called heating-induced adsorption, which achieved a toluene removal efficiency of 69.6 %. By density functional theory (DFT) calculations and changing the metal centers and organic ligands of UiO-66 (Zr) respectively, we disclosed that the heating-induced adsorption was mainly related to the π-π stacking interaction of MOF ligands and toluene. The analysis of samples before and after adsorption showed that the interaction between UiO-66 (Zr) and adsorbed toluene facilitated the charge transfer and prolonged the carrier lifetime, leading to the increase of hydroxyl radicals (•OH) in photocatalysis. Therefore, a synergistic effect between heating-induced adsorption and photocatalysis was proposed by analyzing the adsorption of toluene on UiO-66 (Zr) in detail. This work provided new viewpoint to understand the role of concomitant heat contributed to the adsorption and degradation of toluene during photocatalysis. [ABSTRACT FROM AUTHOR]

Adsorption of volatile gasoline components at oil terminal by using metal organic frameworks (MOFs) is a prospective technology in reducing environment pollution and increasing oil resource recovery. In this study, a typical MOF of HKUST‐1 was facile prepared by solvothermal method and tested in the adsorption of volatile gasoline components. Isobutylene was selected as a model compound. The effects of preparation parameters Cu2+/H3BTC molar ratios, Cu2+ precursors, and solvent compositions on the structure of HKUST‐1 and its subsequent adsorption performance were systematically studied. The synthesized samples were characterized by XRD, SEM, and N2 physisorption. It was found that the HKUST‐1 prepared by using DMF as the unique solvent obtained the highest specific surface area (1076.7 m2/g) and the largest pore volume (0.90 cm3/g). Furthermore, the maximum isobutylene adsorption capacity of 31.9 mg/g was found on the HKUST‐1 which prepared under the conditions of Cu2+/H3BTC = 2, Cu (CH3COO)2 as the Cu2+ precursor, and a solvent composition of DMF:EtOH:H2O = 0:4:3. [ABSTRACT FROM AUTHOR]

In the present paper, a Cu(BDC) metal–organic framework (MOF) is chemically attached to wool via an in-situ synthesizing method. The synthesized novel biocomposite (Cu(BDC)@Wool) was applied as an easily applicable biocomposite to the effective removal of Rifampicin (RIF) from wastewater. Batch adsorption experiments were performed, and the optimum conditions of RIF adsorption (99.3%) were found to be approximately at 25 ppm initial concentration, 1 mg adsorbent, pH 2, time without ultrasonic = 30 min, and time with ultrasonic = 10 which were determined by a response surface methodology. The results of fixed bed experiments showed that better RIF removal was achieved with a low inlet RIF concentration, high adsorbent bed height, and low influent flow rate. The performance of FBAC was maximum (tb = 769, te = 1221 min; %A = 60.6%) at a flow rate of 0.5 mL/min, adsorbent bed height of 7.5 mm, and RIF of 30 ppm. The study of mathematical models shows that the Clark model has the highest correlation with the experimental data. Therefore, the novelty of this work is that ultrasound-assisted removal reduces the equilibration time and can be economically viable for removing RIF from wastewater. [ABSTRACT FROM AUTHOR]

Based on the stable Zr6O4(OH)4 metal clusters, UiO-67 was first applied to the adsorption of U(VI), and its stability and adsorption performance for U(VI) were compared with UiO-66. As the organic ligand was lengthened, UiO-67 had a larger specific surface area and pore volume than UiO-66. The adsorption capacity of UiO-67 for uranium was 1.68 times that of UiO-66 under the same conditions. The chemical stability of UiO series decreased with the extension of organic ligands; for example, the crystalline structure of UiO-67 disintegrated in methanol, ethanol and water. Through the infrared spectra, adsorption isotherms and kinetics fitting, it is concluded that the carboxyl groups of UiO-67 participated in the chemisorption of U(VI), and uranyl ions adsorbed on UiO-67 were not desorbed with the collapse of UiO-67 crystal. This work represents the extension of organic chains reduces the chemical stability of MOFs but improves the adsorption performance of U(VI), which may be applied to predict the structural stability and adsorption capacity of other MOFs containing aromatic dicarboxylate organic linkers. [ABSTRACT FROM AUTHOR]

Elimination of the release of hazardous sulfur compounds into the environment is imperative, and achieving this requires the desulfurization of petroleum products using an effective method. Adsorption desulfurization is gaining as a cost-effective alternative to various other techniques. In this study, cobalt-based metal-organic framework (Co-MOF) and Hybrid MOF: AC adsorbers were prepared using various ratios through the solvothermal method. The objective was to determine the optimal ratio for maximum removal of dibenzothiophene in a model oil through batch process adsorption. The adsorbers were characterized using FTIR, XRD, FESEM-EDS, and N2 adsorption-desorption analysis. The results indicated that a ratio of 1:5 MOF: AC achieved a 98% removal (147.57 mg/g) of DBT among (MOF, AC, 1:1 MOF: AC, 1:2 MOF: AC, and 1:10 MOF: AC) due to its optimal number of active sites and surface area. Furthermore, the optimal conditions for maximum DBT adsorption were a dosage of 0.1 g and a contact time of 2 h. The kinetic study of the adsorber showed conformity with a pseudo-first-order model. [ABSTRACT FROM AUTHOR]

[Display omitted] • CuIn(ina) 4 exhibits preferential adsorption of C 2 H 6 over C 2 H 4. • C 2 H 6 /C 2 H 4 selectivity of CuIn(ina) 4 can be as high as 2.3 at ambient conditions. • Separation potential of CuIn(ina) 4 can reached up to 1578 mmol/L. Purification of ethylene (C 2 H 4) is an essential and energy-intensive process in the petrochemical industry. Adsorption separation using ethane (C 2 H 6)-selective porous adsorbents is a highly efficient and straightforward method for obtaining polymer-grade C 2 H 4 from a binary C 2 H 6 /C 2 H 4 mixture. However, the design and construction of C 2 H 6 -selective adsorbents are very challenging tasks. Herein, we demonstrate a microporous heterometal-organic framework, CuIn(ina) 4 , can preferentially enrich C 2 H 6 than C 2 H 4. Experimental results revealed that CuIn(ina) 4 exhibited remarkable separation performance for the C 2 H 6 /C 2 H 4 mixture with a high C 2 H 6 loading capacity (3.3 mmol/g), high IAST selectivity (2.3) and separation potential (1578 mmol/L for equimolar C 2 H 6 /C 2 H 4 mixture) under ambient conditions. The effectiveness of CuIn(ina) 4 for C 2 H 6 /C 2 H 4 adsorption separation was confirmed by theoretical calculations and breakthrough experiments. [ABSTRACT FROM AUTHOR]

By utilizing a winding carboxylic acid ligand as the linker and 12-connected Hf6 clusters as the metal node, we successfully construct a novel hafnium-based metal–organic framework [Hf6O4(OH)4(DCPB)6]·(Hf-MOF, 1,3-di(4-carboxyphenyl)benzene (H2DCPB)) with ultra-microporous structure. Benefitting from the strong coordination bond between Hf6 clusters and the carboxylic acid ligand, the synthesized Hf-MOF displays extraordinarily high thermal and chemical stability, in which the Hf-MOF can maintain high crystallinity under both acidic and basic aqueous solutions, and its decomposition temperature is as high as about 400 °C. Moreover, the interpenetrated framework can endow the Hf-MOF with ultra-microporous pores, which can provide multiple adsorption sites and play a role in the size sieving effect of CO2 molecules. Thus, the Hf-MOF displays excellent CO2 adsorption and separation performance, in which the maximum CO2 adsorption amount can reach up to 65.5 cm3 g−1 at 273 K and 1 bar, and the selectivities for CO2/CH4 = 0.5/0.5 and CO2/CH4 = 0.05/0.95 are as high as 6.9 and 6.0 under 1 bar at 298 K, respectively, and surpass many reported water stable MOF materials. The commendable stability and the CO2 adsorption/separation ability are of extreme importance for its practical industrial applications. [ABSTRACT FROM AUTHOR]

Activated carbon (AC) from coconut shell, iron‐based metal organic framework (Fe‐MOF), zinc oxide (ZnO), and calcium oxide (CaO) were prepared as adsorbents for the CO2 adsorption process. The adsorption experiments were performed in a self‐designed fixed‐bed small reactor to study the influence of reaction conditions on the CO2 adsorption capacity of adsorbents. According to the findings, Fe‐MOF showed better performance in CO2 adsorption compared to the other selected adsorbents. The results were supported by the high surface area of Fe‐MOF, which was greater than that of AC, ZnO, and CaO. The optimal parameters for CO2 adsorption of all adsorbents were determined in terms of adsorbent dosage, operating pressure, and CO2 adsorption time. [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]

HKUST-1-based composites have been synthesized through the incorporation of synthetic graphite flakes in the MOF synthesis media. The presence of flakes gives rise to high quality HKUST-1 crystals, combining different morphologies (octahedral-shape crystals, cauliflower-shape crystals and truncated pyramids). The incorporation of graphite in the composites improves the structural stability of the embedded nanocrystals upon a conforming step at 377 kg/cm2 (0.5 tons), with limited structural damage (below 10% BET surface area reduction as compared to the 40% observed for pure HKUST-1). Furthermore, composites exhibit a significant improvement in thermal management, associated with the excellent thermal and electrical properties of the graphite microdomains incorporated. The improved stability of the composites is also reflected in the adsorption performance for hydrogen at atmospheric pressure and cryogenic temperatures, with a significant preservation of the adsorption properties (gravimetric capacity, <15% decrease vs powders) in the monoliths containing graphite. The best adsorption performance is achieved with sample HKUST-1@10GF, in monolithic form, with a volumetric excess uptake at 0.1 MPa and −195 °C close to 18.7 g/L. This value is among the best described in the literature for monolithic MOFs under similar adsorption conditions. [Display omitted] • Thermal events in metal-organic frameworks (e.g., HKUST-1) can be modulated through the incorporation of graphite flakes. • The presence of GF in the composites improves the mechanical stability of HKUST-1 upon a conforming step. • HKUST-1@GF monoliths possess excellent adsorption properties for hydrogen at cryogenic temperatures. [ABSTRACT FROM AUTHOR]

[Display omitted] The tunable porous structure of metal organic frameworks (MOFs) plays a crucial role in determining their adsorption performance. In this study, we developed and employed a strategy involving monocarboxylic acid assistance to synthesize a series of zirconium-based MOFs (UiO-66-F 4) for the removal of aqueous phthalic acid esters (PAEs). The adsorption mechanisms were investigated by combining batch experiments, characterization and theoretical simulation. By adjusting the affecting factors (i.e., initial concentration, pH values, temperature, contact time and interfering substance), the adsorption behavior was confirmed as a spontaneous and exothermic chemisorption process. The Langmuir model provided a good fit, and the maximum expected adsorption capacity of di- n -butyl phthalate (DnBP) on UiO-66-F 4 (PA) was calculated to be 530.42 mg·g−1. Besides, through carrying out the molecular dynamics (MD) simulation, the multistage adsorption process in the form of DnBP clusters was revealed on a microcosmic scale. The independent gradient model (IGM) method showed the types of weak interactions of inter-fragments or between DnBP and UiO-66-F 4. Furthermore, the synthesized UiO-66-F 4 displayed excellent removal efficiency (>96 % after 5 cycles), satisfactory chemical stability and reusability in the regeneration process. Hence, the modulated UiO-66-F 4 will be regarded as a promising adsorbent for PAEs separation. This work will provide referential significance in tunable MOFs development and actual applications of PAEs removal. [ABSTRACT FROM AUTHOR]

A metal–organic-framework-based ion trap was designed via tailoring linker functionality as well as free –COOH density. The mixed-linker UiO-66-H2/H4 exhibits higher adsorption for Li+ ions than H4-free UiO-66-H2 because the H4 linker provides an additional –COOH group in the local region. [ABSTRACT FROM AUTHOR]

Light hydrocarbon (C2~C3) adsorption treatment in order to achieve exhaust emission standards of volatile organic compounds (VOCs) is very important and urgent in oil refining and oil storage enterprises. As an important adsorbent, metal‐organic frameworks (MOFs) with large specific surface area and good designability show excellent adsorption properties for light hydrocarbon. In this paper, by replacing the nitrate commonly used in the synthesis of MOFs with alkali metal, and adding a certain proportion of competing carboxylic acid into the reaction system, Cu‐BTC with improved pore structure and adsorption performance of light hydrocarbon was prepared at room temperature. More impressively, 10 L and 100 L scale‐up synthesis of Cu‐BTC were carried out by this method, which remained high light hydrocarbon adsorption capacities, showing great application prospect in the field of VOCs treatment. [ABSTRACT FROM AUTHOR]

Crystalline Zr‐fum‐MOF (MOF‐801) thin films of high quality are prepared on glass and silicon substrates by direct growth under solvothermal conditions. The synthesis is described in detail and the influence of different synthesis parameters such as temperature, precursor concentration, and the substrate type on the quality of the coatings is illustrated. Zr‐fum‐MOF thin films are characterized in terms of crystallinity, porosity, and homogeneity. Dense films of optical quality are obtained. The sorption behavior of the thin films is studied with various adsorptives. It can be easily monitored by measuring the transmission of the films in gas flows of different compositions. This simple transmission measurement at only one wavelength allows a very fast evaluation of the adsorption properties of thin films as compared to traditional sorption methods. The sorption behavior of the thin films is compared with the sorption properties of Zr‐fum‐MOF powder samples. [ABSTRACT FROM AUTHOR]

[Display omitted] Composite materials HKUST-1@MCM-41 and HKUST-1@ BPS based on metal–organic framework HKUST-1 [Cu 3 (btc) 2 , btc = benzene-1,3,5-tricarboxylate] and silicas, i.e. , mesoporous MCM-41 and biporous BPS with a bimodal mesopore size distribution, were prepared by one-step direct growth technique. Methane and ethane adsorption isotherms were measured for the HKUST-1@MCM-41 and HKUST-1@BPS composites in a wide pressure range for the first time. The silica porous structure significantly affects the content and location of HKUST-1 crystallites in these host matrices, and thereby the adsorption selectivities of the composites. [ABSTRACT FROM AUTHOR]

Recent experiments show that the diffusivities of C8 and C10 n‐alkanes in ZIF‐8 are higher than those of C7 and C9, respectively. We investigated this unusual 'odd‐even' effect by simulating the adsorption of C7‐C14 n‐alkanes in ZIF‐8 using hybrid Monte Carlo molecular simulations. The resultant adsorption isotherms, guest‐host energies, isosteric heats, and chain length distributions are analyzed for trends among the n‐alkanes. ZIF‐8 cages filled with n‐alkanes are characterized using a combination of image processing and data science to quantify the differences in packing that occur with chain length. Results indicate that packing changes drastically from C7 to C8 and from C9 to C10, which is consistent with the diffusion trends previously reported in experiments. [ABSTRACT FROM AUTHOR]

One of the barriers to further commercialization of the proton exchange membrane fuel cell (PEMFC) is hydrogen storage. Conventional methods are based on pressurizing the hydrogen up to 700 bar. The focus of this study is to characterize the hydrogen storage capacity of hydrogen tanks filled with MOF-5 at low pressures. Thus, Computational Fluid Dynamic (CFD) was used in a transient condition to analyze the hydrogen storage. Benefiting from the CFD model, three input parameters of the MOF-5, namely, density, specific heat, and conductivity, were utilized to develop an artificial neural network (ANN) model to find the highest mass of adsorption at the lowest required pressure. The optimum possible MOF among 729220 different possibilities, which enables the adsorption of 0.0099 kg at 139 bar, was found using a newly defined parameter called Pressure Adsorption Parameter (PAP). [ABSTRACT FROM AUTHOR]

In recent years, humans have been forced to create effective water treatment methods because of the increasing water contamination caused by various industrial activities. This study focuses on synthesizing a nanocomposite consisting of two metal-organic frameworks based on ZIF-8 with effective antibacterial characteristics and water-stable, highly porous UiO-66-NH 2. After characterizing the synthesized nanocomposite, its application as (i) an adsorbent for methylene blue (MB) removal from a polluted aqueous environment and (ii) an antibacterial agent; was considered. The impact of different factors on the uptake of MB, including dye concentration, adsorption temperature, and the initial pH of the solution, was studied. When the temperature was raised to 45 °C, the maximum adsorption capacity of UiO-66-NH 2 @ZIF-8 for MB improved to 215.78 mg/g. Moreover, the pseudo-second-order model accurately described the experimental MB uptake results. According to the thermodynamic analysis, the spontaneous endothermic adsorption process of MB onto the synthesized UiO-66-NH 2 @ZIF-8 was the consequence of an entropy impact instead of an enthalpy change. Additionally, the synthesized nanocomposite exhibited antibacterial efficacy against two different bacteria, gram-negative E. coli and gram-positive S. aureus , with a minimum inhibitory concentration (MIC) of 30 mg/L against both strains. The results indicated that the synthesized MOF@MOF nanocomposite is efficient in dye removal for water treatment and has excellent potential in disinfection applications. [Display omitted] • iO-66-NH 2 @ZIF-8 was synthesized via a modified method and fully characterized. • MOF@MOF nanocomposite successfully took advantage of the synergistic properties. • UiO-66-NH 2 @ZIF-8 represented a maximum adsorption capacity of 215.78 mg/g. • Nanocomposite had efficient antibacterial activities against E. coli and S. aureus. [ABSTRACT FROM AUTHOR]

Metal–organic framework (MOF)-derived materials have gained an increasing interest and showed potential adsorption features in numerous applications. Significant attempts have been performed to boost the structure, functionality, surface area and porosity in addition to adsorption performance of MOF-derived carbon nanoparticles. Here, nitrogen-doped ZnO/carbon nanoparticles were synthesized by directly pyrolysis of Zn based metal organic framework (ZIF-8) in a nitrogen atmosphere at two different temperatures (600 and 800 °C), followed by chemical impregnation with ZnCl2 solution with ratio (10:1) wt/wt, and thermal activation at 500 °C for 1 h. SEM, TEM, XPS, nitrogen adsorption–desorption method, and TGA characterization techniques were employed to investigate the morphology and structure characteristics. Then, thorough analysis of N doped ZnO/C-(600 and 800), adsorption capacity to remove Remazol brilliant blue reactive (RBBR) dye from aqueous phase was conducted. At room temperature, the porous N doped ZnO/C with high surface area attained a maximum adsorption capacity about 49.3 mg/g and demonstrated a strong adsorption capacity toward RBBR dye. The insights of kinetic, thermodynamic and adsorption isotherm studies of the as-demonstrated samples open up more discussion for MOFs-derived carbon adsorbents for wastewater treatment. [ABSTRACT FROM AUTHOR]

An ultramicroporous metal–organic framework (MOF) constructed from dysprosium(III) and oxalate, termed Dy-F-oxa, is carefully studied for inverse separation of CO2 from C2H2. Adsorption experiments and modeling studies reveal that the high CO2 adsorption is attributed to the preferential sites for CO2 by coordinated water. After the equimolar gas mixture breakthrough experiment, C2H2 can be directly produced as a pure effluent. [ABSTRACT FROM AUTHOR]

In this paper, the reported MOF ([Co(bimip)(H2O)0.5]·0.5H2O) was employed in photocatalytic CO2 reduction, antibacterial, and dye adsorption experiments. The photocatalytic activity of the MOF for CO2 reduction was systematically investigated. The high average CO generation rate of 3421.59 μmol·g−1·h−1 after 12 h confirms the efficient photocatalytic CO2 reduction ability of the MOF. At the same time, the MOF can completely inhibit the growth of S. aureus and C. albicans within 24 h when its concentration reaches 400 μg/mL and 500 μg/mL, respectively. The MOF has an adsorption capacity for CR. The adsorption rate was 83.42% at 60 min, and the adsorption capacity of the MOF for CR reached 500.00 mg·g−1. [ABSTRACT FROM AUTHOR]

Three Ni8-pyrazolate metal–organic frameworks, namely Ni8–NiL1, Ni8–CuL1 and Ni8–CuL2, were prepared using metallosalen-based ligands (NiL1, CuL1, and CuL2). The octanuclear cubic clusters [Ni8(OH)4(H2O)2] render these materials with sufficient robustness, enabling their reusability in water for the removal of methylene blue (MB) over three cycles. Because of π–π stacking interactions, these title materials can effectively adsorb MB and demonstrate an exceptional adsorption capacity (up to 1011.8 mg g−1 for Ni8–CuL2). Meanwhile, these materials show an adsorption preference for MB instead of methyl orange and eosin Y. The kinetic studies reveal that Ni8–NiL1 and Ni8–CuL1 conform to the pseudo second-order model, while Ni8–CuL2 fits to the pseudo first-order model. The adsorption isotherms of the three materials were also determined to obey the Langmuir model. These results indicate that these title materials are promising adsorbents for removing MB from water. [ABSTRACT FROM AUTHOR]

The research on amorphous metal–organic frameworks (aMOFs) is still in its infancy, and designing and constructing aMOFs with functional pores remains a challenge. Two aMOFs based on Co(II) and heterotopic triangular ligands with large conjugated aromatic planes, namely aMOF-1 and aMOF-2, were constructed and characterized by IR, XPS, EA, ICP, XANS and so on. aMOF-1 possesses mesopores, whereas aMOF-2 possesses micropores. The porosity, conjugated aromatic plane and uncoordinated N atoms in the framework allow these aMOFs to adsorb iodine and dyes. The iodine adsorption capacity of aMOF-1 is 3.3 g per g, which is higher than that of aMOF-2 (0.56 g per g), mainly due to the expansion or swelling of aMOF-1 after iodine adsorption. The uptake of cationic dyes by aMOF-2 showed more rapid kinetics and a higher removal rate than that by aMOF-1, mainly due to the difference in the porosity and surface charge. Although the surface charges of aMOF-1 and aMOF-2 are negative, both of them showed significantly faster adsorption kinetics toward anionic dyes, among which methyl orange (MO) and Congo red (CR) can be removed in 5 min. This occurs possibly because the quick adsorption of Na+ ions alters the surface charge of the framework and promotes dye uptake. The adsorption capacities of aMOF-1 for MO and CR reached 921 and 2417 mg g−1, respectively. The correlation data for aMOF-2 are 1042 and 1625 mg g−1, respectively. All adsorption capacities are among the highest compared to many cMOFs. Adsorption in mixed dye solution is found to be charge-dependent, kinetic-dependent, and synergetic in these systems. The porosity, surface charge regulation during adsorption, weak interactions and multiple adsorption processes contribute to the dye adsorption performance. [ABSTRACT FROM AUTHOR]

Post-synthetic modification can be used for structural replacement or functional modification of materials after they have been formed or assembled. It can effectively combine various modification methods for metal-organic frameworks (MOFs) such as defect control, replacement of metal sites, or functionalization of ligands. In this work, organic ligands that incorporate N-functionalities or amino groups were introduced into defective UiO-66 through post-synthetic ligand exchange (PSE) to improve its water adsorption performance. Parameters such as water adsorption capacity, half adsorption value (α), and Henry constant KH were used to characterize the water adsorption performance. After PSE, new ligands in different molar ratios entered the skeleton of UiO-66. The N sites or amino groups on the ligands provided new sites for the adsorption of water molecules. The water adsorption capacity and hydrophilicity of all samples were significantly superior to those of LD-UiO-66, which had almost no defects. H-UiO-66-PyDC samples exhibited the highest ligand replacement ratio and a significant enhancement of water adsorption performance. Compared to the unchanged H-UiO-66, the water uptake of H-UiO-66-PyDC increased from 0.08 g g−1 to 0.23 g g−1 at P/P0 = 0.30 and α decreased from 0.36 to 0.28. After 20 water adsorption/desorption tests, the water uptake of all samples did not decrease, showing excellent cycling stability. These results suggest that the combination of defect modulation and PSE is a potential tool to make UiO-66 more appropriate for applications based on reversible adsorption. [ABSTRACT FROM AUTHOR]

Developing robust multifunctional metal–organic frameworks (MOFs) is the key to advancing the further deployment of MOFs into relevant applications. Since the first report of MFM-300(Sc) (MFM = Manchester Framework Material, formerly known as NOTT-400), the development of applications of this robust microporous MOF has only grown. In this review, a summary of the applications of MFM-300(Sc), as well as some emerging advanced applications, have been discussed. The adsorption properties of MFM-300(Sc) are presented systematically. Particularly, this contribution is focused on acid and corrosive gas adsorption. In addition, recent applications for catalysis based on the outstanding hemilabile Sc–O bond character are highlighted. Finally, some new research areas are introduced, such as host–guest chemistry and biomedical applications. This highlight aims to showcase the recent advances and the potential for developing new applications of this promising material. [ABSTRACT FROM AUTHOR]

Using periodic DFT calculations, we have established the mechanism of the unusual cooperative adsorption of CO gas in an Fe-bistriazolate MOF observed previously. The binding of one CO molecule to FeII triggers structural alteration of the neighbouring Fe centres, reducing the steric energy penalty and aiding cooperative adsorption. This is similar to the entatic state concept proposed for metalloenzymes, and offers novel strategies for selective gas adsorption. [ABSTRACT FROM AUTHOR]

[Display omitted] A nanocomposite based on graphene oxide and cobalt trimesinate was obtained by in situ method and employed in solid-phase extraction of organic pollutants using the triphenylmethane dye, brilliant green, as an example. The maximum adsorption reaches 385.2 mg g–1. [ABSTRACT FROM AUTHOR]

Fluoride is present in several groundwaters due to natural or anthropogenic origins. Although it is necessary for physiological human functions (in small amounts, i.e., 0.5–1.2 mg/L), it could be very harmful when it exceeds the maximum permissible concentration limit of 1.5 mg/L (according to WHO). Among the numerous technologies for removing fluoride from waters, metal–organic framework (MOF) materials are considered to be promising adsorbents due to their advantages of high porosity, high specific surface area, diverse functions and easy modification. In this study, the synthesis of MOFs and the progress of their application to the removal of fluoride from contaminated water, as published in the recent literature mainly over the past five years, are reviewed. The adsorption mechanism(s) and its main characteristics, such as effect of initial fluoride concentration, adsorbent dosage, solution pH, contact time, adsorption capacity, thermodynamic and regeneration studies, etc., for the removal of fluoride with the addition of different MOFs are compared. According to these comparisons, the hydrothermal/solvothermal synthesis method is most commonly used for the preparation of MOFs, whereas higher BET surface areas are shown by specific MOFs based on aluminum metal ions. The main fluoride adsorption mechanisms were found to be electrostatic attraction and/or complexation. The most common pH for conducting experiments was 7.0, but several examined materials were found to be effective over a wide pH range. Four to six regeneration cycles were successfully applied on average, regarding the MOFs under review, whereas in the majority of these cases, the sorption process was found to be endothermic. [ABSTRACT FROM AUTHOR]

Adsorption heat transformation and storage (AHTS) is an environmentally benign and energy-saving alternative to common compression chillers and heat pumps. The low specific power (SP) of adsorption systems is a key drawback that hinders their broader dissemination. The optimization of adsorption dynamics is a prerequisite for SP enhancement. In this work, we studied the dynamics of water vapor adsorption on MOF-801—a promising adsorbent for AHTS. For the first time, two configurations of compact MOF-801 bed, namely, grains glued to the surface of a metal support and thin adsorbent coatings, are prepared, and their porous structure is characterized. The water adsorption dynamics is compared with a common loose grains configuration. The main findings are: (a) the binder can both accelerate and decelerate the water adsorption, and its chemical nature is subject to careful selection; (b) at the initial time, heat transfer between the support and adsorbent bed controls the adsorption rate, and, at a longer time, mass transfer starts to affect it; (c) polyvinylpyrrolidone, bentonite, thermal grease, and hydroxyethylcellulose increase the heat transfer coefficients and accelerate adsorption; polyvinyl alcohol and polyaniline slow it down; and (d) for the coatings prepared with polyvinylpyrrolidone, an SP of 1.6–5.1 kW/kg can be achieved, which is about twice that for the loose grains. The new configurations can be recommended for effective but expensive adsorbents such as MOFs, and their implementation will contribute to the further spread of AHTS technology. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) is a highly toxic, and flammable acid gas that is widely present in confined spaces. However, conventional adsorption materials are inefficient and have poor reuse properties. Metal‐organic frameworks (MOFs) show potential viability as novel materials in gas adsorption. Herein, mainstream MOFs were investigated based on molecular simulation techniques to explore the differences contributing to H2S adsorption. The adsorption process of H2S in MOFs was simulated by Grand Canonical Monte Carlo (GCMC) method, and the diffusion behavior was investigated based on molecular dynamics (MD) simulations. The results showed that the interaction energy and isosteric heat of adsorption were important criteria for determining the adsorption performance of H2S. The regulation of open metal sites could help to further enhance the adsorption of H2S, and the pore structure of MOFs affected the capture of H2S. A higher self‐diffusion rate implies faster H2S capture. Hydrogen bonds affect the trapping efficiency of MOFs for H2S and the relative positions of ligands in the benzene ring cause subtle differences in adsorption. This study provides design strategies for the improvement of new high‐performing MOFs for H2S adsorption in confined spaces. [ABSTRACT FROM AUTHOR]

Iron-based organic frame material MIL-53 (Fe) was synthesized by the hydrothermal method with Cu2+ incorporated to obtain bimetallic composite MIL-53 (Fe, Cu). The structure and morphology of the material were characterized by SEM, XRD, BET, FTIR, XPS, and zeta potential. The adsorption performance of MIL-53 (Fe, Cu) on methyl orange was tested under a variety of conditions, including the effects of pH and material dosage, by the static adsorption test. The results show that under the condition of pH = 7, a temperature of 30°C, and an adsorbent dosage of 20 mg, the removal rate of MIL-53 (Fe, Cu) for methyl orange can reach more than 96% within 4 h, and the maximum adsorption capacity after fitting by the thermodynamic model can reach 294.43 mg/g, showing the excellent adsorption performance of MIL-53 (Fe, Cu) on methyl orange. In addition, by exploring the adsorption mechanism of MIL-53 (Fe, Cu) on methyl orange, it is found that the adsorption of MIL-53 (Fe, Cu) on methyl orange depends on chemical adsorption, as evidenced by combining Fe3+ and Cu2+ in the material with methyl orange molecules to form complexes to achieve adsorption. While the specific surface area of the material had no obvious effect on adsorption, the effects of pH, temperature, and concentration were explored. At a pH of 6.5, greater adsorption occurred at higher temperatures, as determined by thermodynamic model fitting, as well as with higher initial methyl orange molecule concentration. [ABSTRACT FROM AUTHOR]

The efficiency of the metal-organic framework of zinc (MOF-74) and its chitosan composite (CS/ MOF-74) as a potential sorbent for the elimination of azo in addition to thiazine-type dyes from water by subsequent adsorption was studied. The synthesized adsorbents were characterized by various characterization techniques. The chitosan composite exhibited tremendous adsorption properties toward methyl orange (MO) and methylene blue (MB) at pH < 5.5 and pH > 5.5, respectively. The equilibrium data were evaluated by Dubinin-Radushkevich, Langmuir, Freundlich, and Tempkin isotherm models where the Langmuir model was best fitted to the adsorption data. The mono-layer sorption capacity values were found to be in the order 2047 mg/g and 1363 mg/g for MO and MB respectively onto CS/MOF-74 which are almost 6–8 epochs superior to MOF-74 and CS. In addition, pseudo-first, pseudo-second, intraparticle diffusion and Richenberg kinetic models were assessed to the kinetic data where the pseudo-second-order fitted very well to the adsorption data. The higher values of diffusion coefficient confirmed the greater involvement of the film diffusion than the pore and surface diffusion for the elimination of basic as well as acidic dyes onto CS/mOF-74. Thermodynamically, the negative value of isosteric heat of adsorption (ΔH�) concluded that the current study was found exothermic in nature. Moreover, electrostatic interactions, hydrogen bonding, and electron donor–acceptor interactions were suggested as probable mechanisms in the current adsorption process. The current study estimates the industrial importance of a chitosan composite of MOF-74 as it requires a short adsorption equilibrium time for the removal of the dyes and is satisfactorily reusable. [ABSTRACT FROM AUTHOR]

Large-scale application of hydrogen requires safe, reliable and efficient storage technologies. Among the existing hydrogen storage technologies, cryo-compressed hydrogen (CcH 2) storage has the advantages of high hydrogen storage density, low energy consumption and no ortho-para hydrogen conversion. But it still needs higher hydrogen storage pressure when reaching higher hydrogen storage density. In order to reduce hydrogen storage pressure and improve storage density, solid adsorption technology is introduced in CcH 2. Activated carbon and metal-organic framework materials (MOFs) are employed as adsorbents in this paper. The gravimetric/volumetric hydrogen storage capacities of different adsorption tanks are studied and compared with the hydrogen storage conditions of 1–55 MPa at 77–298 K. The results show that the hydrogen storage density of CcH 2 combined with adsorption is higher than that of pure adsorption hydrogen storage, and the storage pressure is lower than that of pure CcH 2 under the same hydrogen storage capacity. And the combination of two hydrogen storage technologies can achieve a high hydrogen storage capacity equivalent to that of liquid hydrogen at a lower pressure. • CcH 2 combined with adsorption can reach higher density with lower storage pressure. • AX-21 plays a negative role when exceed the specific pressure (24 MPa at 77K). • MOFs can significantly improve the density of CcH 2 in a wide range. [ABSTRACT FROM AUTHOR]

We prepared HKUST-1 (Cu3BTC2; BTC3− = 1,3,5-benzenetricarboxylate) using a spray synthesis method with Li doping and defect created via partial replacement of H3BTC with isophthalic acid (IP) to enhance the H2 adsorption capacity. Li-doping was performed by incorporating LiNO3 in HKUST-1 via spray synthesis and subsequent thermal treatment for decomposing NO3−, which enhances H2 uptake at 77 K and 1 bar per unit mass and per unit area from 2.37 wt% and 4.16 molecules/nm2 for undoped HKUST-1 to 2.47 wt% and 4.33 molecules/nm2, respectively. Defect creation via the replacement of the BTC3− linker with the IP2− linker slightly in HKUST-1 skeleton did not affect H2 uptake. Both Li-doping and defect creation significantly enhanced H2 uptake to 3.03 wt%, which was caused by the coordination of Li ions with free carboxylic groups of the created defects via IP replacement. [ABSTRACT FROM AUTHOR]

The binary metal organic framework (MOF) is composed of two heterometallic ions bonded to an organic ligand. Compared with monometallic MOFs, bimetallic MOFs have greatly improved in terms of structure, porosity, active site, adsorption, selectivity, and stability, which has attracted wide attention. At present, many effective strategies have been designed for the synthesis of bimetallic MOF-based nanomaterials with specific morphology, structure, and function. The results show that bimetallic MOF-based nanocomposites could achieve multiple synergistic effects, which will greatly improve their research in the fields of adsorption, catalysis, energy storage, sensing, and so on. In this review, the main preparation methods of bimetallic MOFs-based materials are summarized, with emphasis on their applications in adsorption, catalysis, and detection of target pollutants in water environments, and perspectives on the future development of bimetallic MOFs-based nanomaterials in the field of water are presented. [ABSTRACT FROM AUTHOR]

Exploring the potential of silver metal organic frameworks (Ag‐MOF), we modified it with sulfanilamide (Ag‐MOF‐NH2) to create an efficient means for the adsorption of amoxicillin (AMX) from aqueous solutions. We characterized this new material with various imaging and analyzation techniques. Investigations into adsorption were conducted with varying solution pH, contact time, and adsorbent dosages. Moreover, the kinetics and adsorption isotherms were also tested by different models. Results revealed that equilibrium was reached between the antibiotic and the adsorbents within 100 min, with 1.93 and 2.63 mmol·g−1 as the maximum adsorption capacities of Ag‐MOF and Ag‐MOF‐NH2, respectively. The adsorption of AMX onto the adsorbents is closely in line with the pseudo‐second‐order kinetic model, intraparticle‐diffusion model, and Langmuir isotherm, suggesting that the surface of the adsorbent is homogeneous and that the highest binding sites are filled first. By utilizing this data, an engaging conclusion can be drawn: the process of adsorption is efficient and effective. Optimizing adsorption results with Box–Behnken design (BBD) and Response Surface Methodology (RSM) produced impressive outcomes. Additionally, experiments were conducted on non‐buffered AMX solutions at various NaNO3 concentrations to ascertain the influence of the electrolytes' composition. Surprisingly, its capacity to take up the element was affected by different concentrations and has ability to be reused several times by capacity above 80% for up to four cycles. Discovering the intricate mechanisms behind AMX adsorption, such as electrostatic forces, π–π interactions, H‐bonding, and pore filling, proves to be an invaluable asset in reducing its concentration from real water samples. The mighty potential of Ag‐MOF and Ag‐MOF‐NH2 makes them excellent adsorbents with removal efficiencies ranging between 86% and 97% making them ideal for industrial uses and protecting our environment. [ABSTRACT FROM AUTHOR]