Green Mechanochemical Synthesis of Imine Linked Covalent Organic Frameworks for High Iodine Capture
Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)
Session: 1
Room: Woodley Park
Normanda Brown - Clark Atlanta University
Co-Author(s): Ziad Alsudairy, Clark Atlanta University, Atlanta, GA; Ranjan Behera, Iowa State University, Ames, Iowa; Fazli Akram, Clark Atlanta University, Atlanta, GA; Kuangcai Chen, Georgia State University, Atlanta, GA; Kayla Smith-Petty, Clark Atlanta University, Atlanta, GA; Bria Motley, Clark Atlanta University, Atlanta, GA; Spirit Williams, Clark Atlanta University, Atlanta, GA; Wenyu Huang, Iowa State University, Ames, Iowa; Conrad Ingram, Clark Atlanta University, Atlanta, GA; Xinle Li, Clark Atlanta University, Atlanta, GA
Covalent organic frameworks (COFs) have emerged as promising adsorbents for radioiodine capture, which is of paramount importance for the safe use of nuclear energy. Prominent synthesis for COFs relies on solvothermal conditions requiring long reaction times, hazardous solvents, and high temperatures, which contradict the principles of green chemistry preventing further COF exploration and industrial implementation. Thus, the integration of a synthetic technique with minimal use of solvent, shorter reaction times, and high scalability is highly desired. Mechanochemical synthesis offers a viable, green alternative to address these issues. Mechanochemical synthesis solely relies on mechanical forces such as compression, shear, and grinding to induce chemical transformations. It is recognized by the IUPAC as one of only ten world-changing technologies due to its reaction efficiency, reduced waste, solventless conditions, ease of operation, and cost-effectiveness. This study introduces the use of mechanochemistry for COF synthesis and its performance as an adsorbent for iodine capture. As a result, six distinct COFs with exceptional crystallinity, diverse pore sizes, and functionalities were successfully constructed in a single hour under an air atmosphere and ambient temperature using a RETSCH MM 400 Mixer Mill. When implemented as adsorbents for static iodine vapor capture at 75 °C, four of the mechanically synthesized COFs exhibited outstanding iodine adsorption capacities of 6.5-6.9 g·g−1, equivalent to or exceeding those of their solvothermal counterparts, and most reported COF adsorbents. Additionally, FT-IR and X-ray photoelectron spectroscopy confirm the charge transfer between the COFs and iodine. This work represents the first mechanochemical synthesis of COF adsorbents for iodine capture and will open up a new path for green, facile, and rapid synthesis of high-performing COF adsorbents for environmental remediation.
Funder Acknowledgement(s): This work was supported by the U.S. Department of Energy Early Career Award (DE-SC0022000), the National Science Foundation HBCU-UP-RIA program (2100360), and the PREM program (DMR-2122147).
Faculty Advisor: Xinle Li, xli1@cau.edu
Role: As lead researcher for this project, I conducted the synthesis and characterization of the COFs.