NiFe2O4-based magnetic covalent organic framework nanocomposites for the efficient adsorption of brominated flame retardants from water

A new kind of NiFe 2 O 4 -based magnetic covalent organic framework nanocomposites (NiFe 2 O 4 @COFs) was fabricated through facile synthesis approach under room temperature. The NiFe 2 O 4 @COFs exhibited higher adsorption capacity for brominated flame retardants than carbon nanotube material based on hydrophobic interactions, π-π stacking interaction, and van der Waals forces. In addition, the adsorption isotherm and the kinetic model were more suitable for Langmuir and pseudo-second-order model, respectively. NiFe 2 O 4 -based magnetic covalent organic framework nanocomposites combined with HPLC-UV (absorption wavelength: 214 nm) technology has excellent adsorption performance, which exhibited low detection limits (0.03–1.9 μg L −1 ), wide linear range (0.11–1000 μg L −1 ), good recoveries (91.5–102%) with a relative standard deviation of less than 2.9%. Finally, the prepared magnetic material was successfully used asadsorbents of magnetic solid-phase extraction and applied to the determination of five BFRs from the real water samples. Graphical abstract The adsorption and removal of BFRs by NiFe 2 O 4 @COFs from water samples.