Preparation, characterization and application of CS@PDA@Fe3O4 nanocomposite as a new magnetic nano-adsorber for the removal of metals and dyes in wastewater

This study aimed to develop a novel magnetic chitosan/dopamine/Fe3O4 nano-adsorber (CS@PDA@Fe3O4) for the removal of heavy metal ions and organic dye molecules from aqueous solution. CS@PDA@Fe3O4 was prepared by surface modification of PDA/Fe3O4 nanoparticles with chitosan using IPTES as the cross-linker. The surface structure, composition, and properties of the CS@PDA@Fe3O4 nano-adsorber were characterized by elemental (EDS), spectroscopic (XRD, XPS, and FT-IR), magnetic intensity (VSM), surface and morphological (TEM and SEM) analyses. In order to study its adsorption behavior, equilibrium and kinetics studies were carried out through batch experiments. Additionally, the influences of the pH value, initial concentration, adsorbent dose, and contact time were also evaluated. The CS@PDA@Fe3O4 nano-adsorber exhibited high adsorption capacity especially for Cu(II), with a maximum adsorption capacity of 419.6 mg g−1. The experimental data were well described by the Langmuir isotherm kinetic models.