Abstract The synthesis and characterization of effective magnetic covalent organic frameworks (MCOFs) are presented for the highly efficient adsorption of dimethyl phthalate (DMP), dibutyl phthalate (DBP) and bisphenol A (BPA) from the aqueous environment. The novelty of this research lies in the development of MCOFs through a coprecipitation method that incorporates an innovative silica inner shell. This crucial feature not only prevents aggregation of the magnetic core, which is a significant limitation of conventional adsorbents, but also enables robust interactions between the core and the outer covalent organic framework (COF). The synthesized MCOFs were comprehensively characterised using a variety of techniques. Fourier-transform infrared spectroscopy (FTIR) and vibrating sample magnetometry (VSM) analyses confirmed successful synthesis and strong magnetic properties, while field-emission scanning electron microscopy (FESEM) revealed the presence of spherical, porous structures with small granules. Energy-dispursive X-ray (EDX) spectrometry analysis further confirmed the successful synthesis, showing a material composition of 58.2% Fe, 33.4% O, 4.8% C, and 3.2% Si. Brunauer–Emmett–Teller (BET) analysis showed the MCOFs possess a high surface area of 128.1 m2 g–1 and a pore diameter of 16.8 nm, indicating abundant active sites for adsorption. Under optimal conditions (pH 7, 100 mg adsorbent dosage, and 25-minute contact time) the MCOFs exhibited exceptional adsorption performance, with removal efficiencies of 90.0% for DMP, 86.0% for DBP, and 92.0% for BPA. The kinetic study revealed that the adsorption mechanism follows the pseudo-second-order model, suggesting a significant chemisorption process. Crucially, in situ FTIR analysis provided spectroscopic validation that hydrogen bonding and π–π stacking are the predominant interactions between the MCOFs and the organic contaminants. The developed analytical method achieved low detection limits of 0.0058 mg l−1 for DMP, 0.0079 mg l−1 for DBP and 0.0063 mg l−1 for BPA, indicating high sensitivity for trace-level contaminant detection in real water samples. Furthermore, the adsorbent demonstrated exceptional reusability, maintaining high performance after 15 adsorption–desorption cycles, which is a significant improvement over conventional adsorbents. This study demonstrates that MCOFs with a silica inner shell are a highly promising, stable and sustainable solution for the removal of emerging organic contaminants (EOCs).
Devi et al. (Wed,) studied this question.