Application of 3D magnetic nanocomposites: MXene-supported Fe3O4@CS nanospheres for highly efficient adsorption and separation of dyes

Due to the presence of several hydroxyl and amino groups on the surface, chitosan (CS) has been reported to be a potential candidate to solve the pollution caused by dyes in different industrial wastewater. However, it is associated with the recycling issues. Nano-Fe3O4 has the advantages of easy magnetic separation and surface functionalization, which can improve the efficiency as well as selectivity of separation. However, its tendency for agglomeration can reduce the adsorption capacity. MXene can provide suitable support for both CS and Fe3O4 to construct new MXene@Fe3O4@CS composites. In this study, MXene@Fe3O4@CSmagnetic nanosphere was synthesized by ultrasonic self-assembly to remove Congo red (CR). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier Transform Infrared (FT-IR) spectroscopy were employed to characterize the nanocomposites. According to the batch experiments, the adsorption kinetics were found to predominantly follow quasi-secondary rate kinetics. The adsorption followed Langmuir isotherm model. The adsorption process was found to be endothermic, entropy-driven, and thermodynamically spontaneous process. The adsorption capacity for CR was estimated as 620.22 mg·g-1.