Tailoring the adsorption properties of imidazole-based halogen bonded organic frameworks for anionic dye removal†

Abstract

The diversification of organic ligands is critical for the development of organic frameworks. This study introduces a novel class of imidazole ligand-based [N⋯I⋯N]⁺ halogen bonded organic frameworks (XOFs). By employing various imidazole linkers, including Mlm, DIB, and TIB, we successfully synthesized 1D and 2D XOFs. Characterization techniques such as ¹H NMR, FT-IR, XPS, PXRD, SEM, HRTEM, and SAED confirmed the successful formation of these frameworks. XOF-TIB, a representative 2D XOF, demonstrated exceptional adsorption capacity and selectivity for anionic dyes. The adsorption mechanism was determined to be based on electrostatic interactions. Additionally, XOF-TIB exhibited good reusability and stability. These findings highlight the potential of imidazole ligands for the construction of XOFs and the promising applications of these materials in environmental remediation, particularly for anionic dye removal from wastewater.