Related Experiment Video
Updated: Sep 19, 2025
An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter
Published on: July 13, 2018
Distinct Effect of Conjugation Units in Covalent Organic Frameworks on Iodine and Gold Adsorption
1School of Chemical Science and Engineering, Tongji University, Siping Road 1239, Shanghai 200092, China.
Abstract:
The capture of radioactive iodine and recovery of precious metal gold have become hot research topics in recent years. Covalent organic frameworks (COFs) linked by imine bonds are ideal adsorbents for iodine and gold due to their abundance of N sites. The N site as an electron-deficient group has been well-discussed; therefore, in the present work, we explored the effect of its conjugation degree on gold and iodine adsorption by modulating the electron-rich unit. As the degree of donor conjugation increases (COF-Be, COF-Na, and COF-An), the adsorption of gold rises (492.0, 711.3, and 1080.7 mg/g), which is the opposite for iodine (3.8, 2.9, and 2.02 g/g). By characterization and theoretical calculations, the increase in the conjugation degree enhances the reduction of gold by COFs. In contrast, the decrease in the density of N sites and the decrease in the pore volume led to a decrease in the adsorption capacity for iodine. The work clarifies the differences in the adsorption processes of gold and iodine by these three COFs and provides a new idea to optimize the adsorption capacity of gold by adjusting the degree of donor conjugation of COFs.
More Related Videos
11:38In situ FTIR Spectroscopy as a Tool for Investigation of Gas/Solid Interaction: Water-Enhanced CO2 Adsorption in UiO-66 Metal-Organic Framework
Published on: February 1, 2020
06:44From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Related Concept Videos
02:45Alkyl Halides
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
02:51Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
03:45Formation of Complex Ions
02:42Valence Bond Theory
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...