Magnetic Covalent Organic Framework Composites for Wastewater Remediation

Abstract

Covalent organic frameworks (COFs) with high specific surface area, tailored structure, easy functionalization, and excellent chemical stability have been extensively exploited as fantastic materials in various fields. However, in most cases, COFs prepared in powder form suffer from the disadvantages of tedious operation, strong tendency to agglomerate, and poor recyclability, greatly limiting their practical application in environmental remediation. To tackle these issues, the fabrication of magnetic COFs (MCOFs) has attracted tremendous attention. In this review, several reliable strategies for the fabrication of MCOFs are summarized. In addition, the recent application of MCOFs as outstanding adsorbents for the removal of contaminants including toxic metal ions, dyes, pharmaceuticals and personal care products, and other organic pollutants is discussed. Moreover, in‐depth discussions regarding the structural parameters affecting the practical potential of MCOFs are highlighted in detail. Finally, the current challenges and future prospects of MCOFs in this field are provided with the expectation to boost their practical application.

Thiol–Ene Click Reaction Modified Triazinyl-Based Covalent Organic Framework for Pb(II) Ion Effective Removal

“…In recent years, covalent organic frameworks (COFs) as heavy metal adsorbents have been widely studied. − As a new class of crystalline porous organic polymers, COFs can be used as an ideal platform to study the adsorption mechanism and factors affecting adsorption activity due to their ordered pore structure, structural stability, easy functionalization, and designability of the environment around the active site. ,,− However, currently, most of the COFs are prepared by the solvothermal method, which requires high temperatures and is unfavorable for large-scale preparation and applications of Pb 2+ adsorption. At present, copper-catalyzed azide–alkyne cycloaddition (CuAAC), , “thiol–ene” click reactions, , Suzuki–Miyaura cross-coupling, and activated esters are emerging as the mainstream ways of introducing active sites in COFs.…”

Fe3O4 Nanoparticle/Hyper-Cross-Linked Polymer Composites for Dye Removal

“…Various advanced materials have been used for the modification of magnetic nanoparticles. They include metal–organic frameworks, , ionic liquids, , molecularly imprinted polymers, , graphene oxides, , carbon nanotubes, , carbon-based quantum dots, , graphitic carbon nitrides, and covalent organic frameworks. , Nevertheless, these magnetic composites still exhibit several shortcomings. The carbon-based adsorbents are characterized by a single interaction force.…”

Effective Adsorption–Desorption Kinetic Study and Statistical Modeling of Bentazon Herbicide Mediated by a Biodegradable β-Cyclodextrin Cross-Linked Poly(vinyl alcohol)–Chitosan Hydrogel

“…However, these approaches have several disadvantages, such as time-consuming sample preparation, high interference, being economically unfeasible, inefficient removal, etc., which make them unfeasible for routine environmental monitoring. In contrast, adsorption processes are attractive for their simple protocol, flexibility, versatility, easy handling, and lower cost without suffering the limitations of above-mentioned methods, , and they present a suitable approach for remediation of BZ from wastewater. − Hence, some attempts have been made for the removal of BZ by using activated carbon, functionalized silica, carbon cloth, biochar, composites, etc. Recently, adsorbents based on polysaccharides, like hydrogels, have been employed for the adsorption of hazardous materials, pesticides, dyes, and heavy metals .…”

“…Different approaches, including photodegradation, 13 electrochemical oxidation processes, 14 spectrofluorometric techniques, 15 chemical coagulation, 16 membrane processes, 17 ing sample preparation, high interference, being economically unfeasible, inefficient removal, etc., which make them unfeasible for routine environmental monitoring. In contrast, adsorption processes are attractive for their simple protocol, flexibility, versatility, easy handling, and lower cost without suffering the limitations of above-mentioned methods, 18,19 and they present a suitable approach for remediation of BZ from wastewater. 20−22 Hence, some attempts have been made for the removal of BZ by using activated carbon, 20 functionalized silica, 23 carbon cloth, 12 biochar, 11 composites, etc.…”