Application of metalated covalent organic frameworks (MCOFs) for adsorption and separation of pollutants: a review study

Numerous chemical and physical features of porous materials depend on the presence of metal ions in their structure. Metalated organic covalent frameworks (MCOFs), which are formed by combining organic covalent frameworks (COFs) with metal ions, integrate high-stability covalent bonds with flexible coordinate bonds and thus have the common characteristics of COFs and metal species such as extraordinary chemical stability, regular structure, and flexibility in design, high mechanical strength, low density, and permanent porosity. These characteristics have caused MCOFs to be used in various fields such as energy storage, measurement and analysis, biomedical applications, catalysis, molecular adsorption, and separation. Our review attempts to provide an overview of the recent research progress on the applications of MCOFs for the adsorption and separation of different pollutants. Strategies used for MCOF-based adsorption and separation applications, as well as existing challenges and future directions for research in this area, are summarized.