Metal organic frameworks (MOFs) are considered as a group of compounds, either metal ions or clusters, harmonized with organic ligands to form one or some dimensional structures. In addition to resilient bonds between inorganic and organic units, reticular synthesis creates MOFs, accurate selection of constituents of which can produce high thermal and chemical stability and crystals of ultrahigh porosity. Other solids have not shown the same accuracy normally used in chemical modification and even the capability of increasing their metrics with no modification of the underlying topology. With shape of building units and chemical compositions multiplying based on specific structures, MOFs might result in compounds that propose a synergistic mixture of features. This study presents up to date advances in both synthesis methods of MOFs and structural characteristics. Furthermore, the use of MOFs in different fields such as the removal of absorption and separation of toxic substances from gas and liquid, catalysts, a variety of sensors, storage of clean energies and environmental applications, medical and biological applications, and optoelectronic equipment is included.

A review on metal-organic frameworks: Synthesis and applications

Ultrathin two-dimensional metal-organic frameworks (2D MOFs) have recently attracted extensive interest in various catalytic fields (e.g., electrocatalysis, photocatalysis, thermocatalysis) due to their ultrathin thickness, large surface area, abundant accessible unsaturated active sites and tunable surface properties. Besides tuning the intrinsic properties of pristine 2D MOFs by changing the metal nodes and organic ligands, one of the hot research trends is to develop 2D MOF hybrids and 2D MOF-derived materials with higher stability and conductivity in order to further increase their activity and durability. Here, the synthesis of 2D MOF nanosheets is briefly summarized and discussed. More attention is focused on summaries and discussions about the applications of these 2D MOFs, their hybrids and their derived materials as electrocatalysts, photocatalysts and thermocatalysts. The superior properties and catalytic performance of these 2D MOF-based catalysts compared to their 3D MOF counterparts in electrocatalysis, photocatalysis and thermocatalysis are highlighted. The enhanced activities of 2D MOFs, their hybrids and derivatives come from abundant accessible active sites, a high density of unsaturated metal nodes, ultrathin thickness, and tunable microenvironments around the MOFs. Views regarding current and future challenges in the field, and new advances in science and technology to meet these challenges, are also presented. Finally, conclusions and outlooks in this field are provided.

2D metal-organic framework-based materials for electrocatalytic, photocatalytic and thermocatalytic applications.

This research tried to perform a comprehensive evaluation of dye (Reactive Red 120 (RR120)) removal by the surfactant-modified montmorillonite (Mt). For this purpose, the experiments were carried on at two levels. In the first level, the adsorption behavior of cetylpyridinium chloride monohydrate (CPCM) and alkyl dimethyl benzyl ammonium chloride (ADBAC) onto Mt was assessed by electrical conductivity technique. In this manner, the critical micelle concentration (CMC) point of ADBAC and CPCM were achieved 0.41 g/L and 2.02 g/L, respectively. Next, modified Mt, as efficient adsorbent, was utilized to toxic anionic dye adsorption from model wastewater. The attraction force between the positive surface charge of modified Mt and the negative charge of RR120 dye molecules leads to the high adsorption capacity. The mostly-known adsorption isotherm models were applied to the experimental data. The obtained data of surfactants adsorption onto Mt, as well as the adsorption data related to RR120 dye removal using modified Mt, were well fitted with the Langmuir isotherm model. The maximum Langmuir capacity for CPCM and ADBAC adsorption by Mt was achieved 183.0 mg/g and 311.8 mg/g, respectively. This amount was found 227.3 mg/g and 243.09 mg/g regarding RR120 adsorption by ADBAC and CPCM-modified Mt, respectively. Also, the hydration inhibitive ability of surfactants was investigated, and the characteristic of them was examined through extensive inhibition evaluation experiments, including settlement, zeta potential, XRD, FTIR, particle size, and SEM analyses.

Surface modified montmorillonite with cationic surfactants: Preparation, characterization, and dye adsorption from aqueous solution

Aryl diazonium salts are versatile building blocks in organic synthesis In light of the ever-increasing importance of aryl diazonium salts spanning most disciplines of the chemical sciences, we review the recent development of aryl diazonium chemistry over the past seven years (2013-2020) Special emphasis is put on various new transformations involving the generation of radical intermediates via thermal, photochemical, and electrochemical means Recent advances in the development of transition metal-catalyzed reactions using aryl diazonium salts are also reviewed Together, these newly developed transformations significantly expand the synthetic chemist's repertoire of aromatic carbon-carbon and carbon-heteroatom bond forming methods using aryl diazonium precursors, providing powerful tools for the synthesis and modification of complex molecular scaffolds

Recent Development of Aryl Diazonium Chemistry for the Derivatization of Aromatic Compounds

Adsorption as a technique is preferred to these other methods in the mitigation of methyl orange (MO) because of its simplicity in design and operation, indifferent sensitivity towards toxicants and low operational cost. This study is aimed at evaluating the performance of various adsorbent groups in the mitigation of MO from aqueous solutions. It will help reduce the arbitrary choice of adsorbent types for MO adsorption leading to a reduction in the amount of published literature with little/incremental contributions to the field. The study was based on an analysis of over 240 published works of literature on the subject within the last 5 years. The adsorbents were classified into the following seven groups based on their chemical composition; biosorbents, activated carbon, biochar, clays and minerals, polymers and resins, nanoparticles, and composites. In terms of frequency of utilisation of adsorbent group, composites were the most frequently used (>40%). It was observed that nanoparticles and polymers were the most frequently used constituents in the manufacture of composite adsorbents for MO. The choice of nanoparticles in composite adsorbents could be due to their flexibility in going into the matrices of other material types due to their small sizes. Polymers also act as good matrices for immobilising other composite constituents. Nanoparticles was the best adsorbent group for MO uptake. Clays and minerals had the greatest proportion of adsorbents with MO uptake capacity greater than the 1000 ​mg/g threshold.

Adsorption of methyl orange: A review on adsorbent performance

Modification of montmorillonite by Gemini surfactants with different chain lengths and its adsorption behavior for methyl orange

A molybdenum disulfide and 2D metal-organic framework nanocomposite for improved electrocatalytic hydrogen evolution reaction

A group of Ni/SiO2 catalysts was prepared via the complexed-impregnation method with different amounts of citric acid (Ni–C/SiO2). The Ni–C/SiO2 and Ni/SiO2 prepared by the conventional impregnatio...

A High-Performance Ni/SiO2 Prepared by the Complexed-Impregnation Method with Citric Acid for Carbon Dioxide Reforming of Methane

Facial strategy for radical species through Ag(I)-mediated oxidation of the alkyl trifluoroborates

A series of Zn–Cr based catalysts modified by K promoter has been prepared by different methods and their performances for iso-butanol formation from biomass syngas were investigated in a fixed bed reactor. The ZnCr-c catalyst which was prepared by co-precipitation method showed the best catalytic performance for iso-butanol formation, over which ca. 30% of CO conversion and ca. 20% of iso-butanol selectivity were achieved. Multi-characterization studies were then conducted to reveal the internal causes for different performances for iso-butanol formation over different catalysts including high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), temperature programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). The results reveal that ZnCr-c catalyst contains the maximum amount of non-stoichiometric spinel among all the catalysts. This fact implies that the non-stoichiometric spinel is the active phase for iso-butanol synthesis from syngas. The reducibility, texture parameters and basic property of catalysts are further important factors for the formation of iso-butanol over Zn–Cr based catalysts from biomass syngas.

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Siyi Ding

Papers

Modification of montmorillonite by Gemini surfactants with different chain lengths and its adsorption behavior for methyl orange

A molybdenum disulfide and 2D metal-organic framework nanocomposite for improved electrocatalytic hydrogen evolution reaction

A High-Performance Ni/SiO2 Prepared by the Complexed-Impregnation Method with Citric Acid for Carbon Dioxide Reforming of Methane

Facial strategy for radical species through Ag(I)-mediated oxidation of the alkyl trifluoroborates

The role of non-stoichiometric spinel for iso-butanol formation from biomass syngas over Zn─Cr based catalysts