Imaging Solvent‐Triggered Gaseous Iodine Uptake on Single Covalent Organic Frameworks

Abstract

Covalent organic frameworks (COFs) are promising solid absorbents for the treatment of gaseous iodine. However, extensive efforts are still focused on empirical optimizations of specific binding sites and pore structures in COFs, and the chemical control of gaseous iodine uptake on COFs remains challenging. In this study, the chemically triggered sorption properties of COF-300 for I 2 vapors at the single-particle level with the dark-field microscope (DFM) are explored. The present operando single-particle DFM imaging method enables the direct visualization of an adsorption activity transformation from inactive COF-300 to active solvated COF-300 toward gaseous I 2 vapors. Exploiting the useful reaction information from time-lapsed DFM images, the tunable adsorption performance of solvated COF-300 is quantitatively compared by various solvents. The results illustrate that the isopropanol (IPA)solvated COF-300 achieves the optimum adsorption capacity for I 2 among the absorbents. The reaction mechanism is elucidated to be the channel size enlargement and modification of internal surface chemistry in the IPA-solvated COF-300, producing a stable I 2 /IPA-solvated COF-300 complex after the sorption reaction. The present chemical control of the sorption behavior of COF-300 revealed by DFM opens up a new fundamental paradigm for rationally developing high-performance COF-based absorbents for removing I 2 vapors.

Near-infrared visualisation of single microparticle electrochemistry for batteries

“…This part of lithium ion battery science features complex multidimensional data, which means opportunities of being efficiently elucidated with the aid of artificial intelligence. 35 As such, this near-infrared optical methodology is demonstrated to offer potential opportunities for in situ accessing the redox electrochemistry of practical battery particles as well as other intraparticle kinetic analyses 36,37 at the single particle level.…”

Rapid, high-capacity adsorption of iodine from aqueous environments with amide functionalized covalent organic frameworks

“…6 In addition to its ability to affect human health, 129 I has a very long half-life of ∼10 million years. 7,8 Therefore, it is vital and necessary to develop new materials for iodine capture given the detrimental impacts. Current methods for removing radioactive iodine from different industrial waste streams include wet scrubbing (using alkaline solutions like NaOH or Hg(NO 3 ) 2 ) as well as solid phase adsorption (using silver salts, zeolites, minerals containing bismuth oxyiodide, activated carbon and others).…”

Rapid, High-Capacity Adsorption of Iodine from Aqueous Environments with Amide Functionalized Covalent Organic Frameworks

“…6 In addition to its ability to affect human health, 129 I has a very long half-life of ~10 million years. 7,8 Therefore, it is vital and necessary to develop new materials for iodine capture given the detrimental impacts. Current methods for removing radioactive iodine from different industrial waste streams include wet scrubbing (using alkaline solutions like NaOH or Hg(NO3)2 as well as solid phase adsorption (using silver salts, zeolites, minerals containing bismuth oxyiodide, activated carbon and others).…”