Adsorption of iodine in metal-organic framework materials

Nuclear power will continue to provide energy for the foreseeable future, but it can pose significant challenges in terms of the disposal of waste and potential release of untreated radioactive substances. Iodine is a volatile product from uranium fission and is particularly problematic due to its solubility. Different isotopes of iodine present different issues for people and the environment. 129I has an extremely long half-life of 1.57 × 107 years and poses a long-term environmental risk due to bioaccumulation. In contrast, 131I has a shorter half-life of 8.02 days and poses a significant risk to human health. There is, therefore, an urgent need to develop secure, efficient and economic stores to capture and sequester ionic and neutral iodine residues. Metal-organic framework (MOF) materials are a new generation of solid sorbents that have wide potential applicability for gas adsorption and substrate binding, and recently there is emerging research on their use for the selective adsorptive removal of iodine. Herein, we review the state-of-the-art performance of MOFs for iodine adsorption and their host-guest chemistry. Various aspects are discussed, including establishing structure-property relationships between the functionality of the MOF host and iodine binding. The techniques and methodologies used for the characterisation of iodine adsorption and of iodine-loaded MOFs are also discussed together with strategies for designing new MOFs that show improved performance for iodine adsorption.

A Cu-BTC metal–organic framework (MOF) as an efficient heterogeneous catalyst for the aerobic oxidative synthesis of imines from primary amines under solvent free conditions

A Cu-BTC MOF catalyst has been identified as an efficient and reusable heterogeneous catalyst for imine formation under neat conditions.

A 3D [WS4Cu4]2+ cluster-based material with high iodine uptake capability

A three-dimensional heterothiometallic [WS₄Cu₄]²⁺ cluster-supported porous framework material with an unusual topology, which displays good performance in iodine uptake.

Design, synthesis and characterization of copper-based coordination compounds with bidentate (N,N and N,O) ligands: reversible uptake of iodine, dye adsorption and assessment of their antibacterial properties

This work presents the synthesis of close-packed copper complexes with an uncommon ability for dye and iodine adsorption and antibacterial activities.

A series of porous interpenetrating metal–organic frameworks based on fluorescent ligands for nitroaromatic explosive detection

Four porous interpenetrated fluorescent MOFs based on π-electron-rich N-donor ligands can effectively detect nitroaromatic explosives and exhibit highly sensitive responses to 2,4,6-trinitrophenol.

Self-assembly of two supramolecular indium(iii) metal–organic frameworks for reversible iodine capture and large band gap change semiconductor behavior

Conjunction of benzimidazole and metal In(iii) to construct supramolecular MOFs opens up an ingenious direction for synthesizing materials with multi-functionality.

A two-component hydrogelator from citrazinic acid and melamine: synthesis, intriguing role of reaction parameters and iodine adsorption study

Melamine and citrazinic acid, upon solid-state grinding, produced a two-component gelator which selectively gelates water or a mixed-solvent system having water as one of the solvents. The dried hydrogel was porous and shows adsorption and storage of molecular iodine.