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

The development of new porous materials has attracted intense attention as adsorbents for removing pollutants from wastewater. However, pure inorganic and organic porous materials confront various problems in purifying the wastewater. In this work, we integrated a covalent organic framework (TpPa-1) with an inorganic zeolite (TS-1) for the first time via a solvothermal method to fabricate new-type nanoadsorbents. The covalent organic framework/zeolite (TpPa-1/TS-1) nanoadsorbents combined the merits of the zeolite and COF components and possessed efficient adsorptive removal of organic contaminants from solution. Structural morphology and chemical composition characterization by powder X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric analysis demonstrated the successful preparation of TpPa-1/TS-1 composite nanoadsorbents. The resultant composite adsorbent TpPa-1/TS-1 removed rhodamine B at 1.7 and 2.6 times the efficiency of TpPa-1 and TS-1, respectively. Additional investigation revealed that the Freundlich adsorption isotherm and the pseudo-second-order kinetic model could be employed to represent the adsorption process more appropriately. Thermodynamic calculation analysis showed that the adsorption process proceeded spontaneously and exothermically. Besides, the effects of pH, absorbent mass and ionic strength on the adsorption performance were systematically investigated. The prepared composite adsorbent showed a slight decrease in removal efficiency after eight cycles of repeated use, and real water environment experiments also showed the high stability of the adsorbent. The enhanced performance can be attributed to electrostatic interaction, acid-base interaction, hydrogen bonding and π–π interactions. [Display omitted] • New covalent organic framework/zeolite nanoadsorbents were prepared. • Adsorbents exhibited excellent removal efficiency and kinetics for typical pollutants. • Adsorbents possessed good recyclability and were effective for real water samples. • The possible removal mechanisms through multiple interactions were proposed. [ABSTRACT FROM AUTHOR]

High-alumina fly ash (HAFA) is one of the categories of industrial solid wastes and the extraction of aluminum from HAFA could offer an alternative to the commercially available aluminum salts to prepare advanced materials such as Al-based metal–organic frameworks (MOFs). In the present work, eco-MIL-53(Al) has been successfully fabricated through a one-pot method by reacting the HAFA or sintered product (obtained by alkaline fusion activation treatment of HAFA) with terephthalic acid, respectively. Furthermore, their adsorption properties for the dye molecules in wastewater were investigated. In addition, the sintering conditions and decomposition rates of HAFA were explored. Experimental results manifested that the mixture of HAFA and Na 2 CO 3 was sintered at 890 °C for 90 min, the ash-alkali ratio was 1:0.6, and the optimal decomposition rate could reach 97.75%. The obtained eco-MIL-53(Al) could maintain a stable skeleton up to 500 °C. The scanning electron microscopy results demonstrated that the MIL-53(Al) grew into columnar crystals from the surface of the raw material, and the addition of HCl in the synthesis process was beneficial to the formation of larger grains. Particularly, the SINTER-MIL had excellent adsorption performance for methylene blue (MB). The maximum adsorption amount of MB was calculated to be 28.80 mg g–1 at room temperature, and its adsorption removal rate could reach 79.53% at equilibrium adsorption. The MB adsorption onto the obtained samples conformed to the pseudo-second-order model and the Freundlich model, respectively. Therefore, the employment of sustainable aluminum sources such as HAFA to prepare MOFs has certain significance for economical aspects and environmental protection. [Display omitted] • High-alumina fly ash was used as sustainable aluminum sources to synthesize eco-MOFs. • The activation and the synthesis conditions were optimized systematically. • The adsorption properties of the obtained eco-MIL-53(Al) were investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] • New MIL-53(Fe)@TiO 2 composites were fabricated via a one-pot solvothermal process. • The MIL-53(Fe)@TiO 2 = 1:2 showed boosted adsorption performance for tetracycline. • The MIL-53(Fe)@TiO 2 = 1:2 also displayed photocatalytic capability for tetracycline. • The synergism and active species (•O 2 − and •OH) enhanced the elimination ability. • A possible mechanism for tetracycline degradation by MIL-53(Fe)@TiO 2 was proposed. Novel semiconductor–MOFs composites based on TiO 2 and MIL-53(Fe) were constructed using a facile one-pot solvothermal process and acted as effective visible-light responsive adsorptive photocatalysts for the removal of tetracycline (TC). The resultant MIL-53(Fe)@TiO 2 composites were characterized by comprehensive analyses, ESR, and photoelectrochemical measurements. Experimental results showed that the synthesized MIL-53(Fe)@TiO 2 composites possessed enhanced adsorption and excellent photocatalytic activity for TC solution under visible light irradiation. Among all the composites, the MIL-53(Fe)@TiO 2 = 1:2 exhibited optimal removal performance compared with pristine MIL-53(Fe) and TiO 2. The results of UV–vis DRS verified the visible light absorption range of the prepared composite was improved, and the results of the Nyquist plot illustrated that the transfer ability of photo-generated charge carriers was boosted. More importantly, the ESR results showed that the •O 2 − and •OH active species played a crucial role in photocatalytic reactions. The enhanced photocatalytic ability was due to not only the fabrication of the n-n type heterojunction photocatalysts, which could provide more active species, but also the synergy between MIL-53(Fe) and TiO 2 in the composites. A possible reaction mechanism was proposed to elucidate the reason for the photocatalytic performance enhancement. Our findings may open up a new field for Fe-MOF and semiconductor composite materials in removing TC in visible light. [ABSTRACT FROM AUTHOR]

• MOF – silica composites for advanced applications have been reviewed. • The fabrication strategies classified into three categories are presented. • The main applications in adsorption, catalysis, energy, and others are discussed. • Conclusions and perspectives for MOF – silica composites are proposed. The fabrication of novel porous materials remains of great interest because of their intriguing architectures, various properties, and promising applications. As typical porous materials with high crystallinity, metal–organic frameworks (MOFs) have attracted continuous attention to the scientific community. However, poor stability and monotonous pore structures hinder their practical and/or advanced applications. To address these concerns, many researchers have devoted themselves to the topics of hierarchical structures and composites by the combination of different components. The present review focuses on the recent advances in MOF–silica composites, where the silica materials can be porous or nonporous. It first provides the fundamentals of porous materials, including zeolites, mesoporous silica, and MOFs, and then shifts to the fabrication of MOF–silica composites. In the following sections, the emphasis of the discussion is placed on the applications of MOF–silica composites, such as adsorption, catalysis, drug release, extraction, magnetism, and sensing. Furthermore, the applications of MOF–silica composites-derived carbon materials are also reviewed and discussed in detail. Finally, it summarizes the achievements of MOF–silica composites and gives an outlook on future research. [ABSTRACT FROM AUTHOR]

Currently, the issue of antibiotic pollution in water bodies has been increasingly capturing people's attention. The use of high-performance adsorbents for removing antibiotics from water is an effective solution. In this study, NH 2 -MIL-53(Fe) and triazine-containing Tp-TTA were successfully combined to produce a novel MOF/COF composite named NMF/TT, capable of effectively adsorbing and removing antibiotics. Various characterization techniques were employed to determine the properties and morphology of NMF/TT, and the adsorption performance for four representative antibiotics (tetracycline, ciprofloxacin, ofloxacin, and norfloxacin) was investigated. Results indicated that NMF/TT-90 exhibited the optimal adsorption quantity, significantly enhancing the adsorption quantity compared to the pure components. The adsorption processes of the four antibiotics followed the pseudo-second-order kinetic model and Langmuir isotherm model. Among them, NMF/TT-90 demonstrated the highest adsorption quantity for tetracycline, with a maximum adsorption quantity of 118.48 mg g−1, and also exhibited an adsorption quantity of 55.93 mg g−1 for ciprofloxacin. Thermodynamic results confirmed the spontaneous nature of the adsorption processes for tetracycline and ciprofloxacin. NMF/TT-90 showed the strongest adsorption quantity for tetracycline at pH 7. Furthermore, the effects of adsorbent dosage, interfering ions, real water samples, and the regenerability of the adsorbent were investigated. The high adsorption quantity of the adsorbent is attributed to the π–π interactions, hydrogen bonding, and coordination between NMF/TT-90 and antibiotic molecules, as well as the possible defect effects during the composite formation process. [Display omitted] • New MOF/COF hybrid adsorbents (NMF/TT) were fabricated for the first time. • The NMF/TT adsorbents can efficiently adsorb and remove a variety of antibiotics. • The NMF/TT adsorbents exhibited good anti-anion interference ability. • The potential adsorption mechanisms of antibiotics by NMF/TT were proposed. [ABSTRACT FROM AUTHOR]

Facing ubiquitous fluoride pollution in aquatic environments and ever-increasing discharge of coal fly ashes, this study aims to in situ synthesize a kind of Al-based metal–organic framework eco-material (eco-MOF) using high-alumina fly ash as metal raw material, and apply the obtained adsorbent to efficiently adsorb fluoride in water. The synthesized eco-MIL-53(Al) exhibits excellent thermal stability, showcasing a consistent morphology of fine columnar crystals and possessing a high specific surface area (353 ​m2·g−1). Moreover, the adsorption isotherm demonstrates a strong agreement with the Langmuir isotherm model, indicative of a maximum uptake quantity of 160 ​mg·g−1 ​at 318 ​K. In addition, fluoride adsorption experiments demonstrate that an increased dosage enhances the adsorption efficiency, the higher water pH value diminishes the removal efficiency, and the impact of coexisting anions is minimal. Also, the adsorption capacity is augmented with increasing temperature at high initial fluoride concentrations, but shows negligible variation at low initial fluoride concentrations. It is worth noting that the desiliconization filtrate can be applied to synthesize ZSM-5 zeolite, realizing the total utilization of fly ash. The present work provides a novel platform that would serve as a mutually beneficial reference for managing the environmental risks of fluoride and waste resource utilization. [Display omitted] [ABSTRACT FROM AUTHOR]

Since the human consumption of coal is increasingly growing and coal-based solid wastes are discharged in large quantities, the resource utilization of coal-based solid wastes has been paid more attention. In the present work, for the first time, the coal gasification fine slag is subjected to prepare ZSM-5 zeolites with ultra-low n (SiO 2)/ n (Al 2 O 3) ratios (less than 20) and hierarchical pore structures. The increase in the concentration of the alkaline extract leads to the decrease of the crystallinity, the irregularity of the microscopic morphology, and the decrease of the specific surface area, resulting in the in-situ generation of mesopores within ZSM-5. Moreover, adsorption experiments demonstrate that ZSM-5-2M exhibits the best methylene blue adsorption performance at the pH of 9 with a removal rate of up to 82.07%, and it also has good adsorption performance in simulated real water samples. Furthermore, the adsorption performance of ZSM-5-2M on the malachite green, Rhodamine B, Congo red, and methyl orange has been investigated and it is found to be very effective for the adsorption of cationic dyes, and its adsorption performance for methylene blue and malachite green is reduced in the presence of anions. [Display omitted] • Hierarchical porous ZSM-5 zeolites were synthesized from coal gasification fine slag. • The obtained ZSM-5 zeolites possessed ultra-low silica-to-alumina ratios. • The morphology and textural properties can be tuned by varying alkaline conditions. • The maximum adsorption efficiency of MB by obtained ZSM-5 reached 82.07%. • The obtained ZSM-5 showcased selective adsorption performance for dyes in wastewater. [ABSTRACT FROM AUTHOR]