Synthesis and characterization of magnetic halloysite-iron oxide nanocomposite and its application for naphthol green B removal

In the present work, a magnetic nanoadsorbent was prepared by incorporating magnetic iron oxide nanoparticles (Fe3O4) on the surface of halloysite nanotubes. The structure and morphology of the synthesized nanocomposite were investigated by using of FT-IR and field emission-scanning electron microscope. This nanoadsorbent was successfully applied for removal of naphthol green B from the aqueous solutions. Kinetic studies show the adsorption of naphthol green B on the surface of adsorbent could be characterized by the pseudo-second order model. Also, investigation of adsorption isotherms showed that the Langmuir model fitted better than the Freundlich model and naphthol green B forms a mono-layer on the surface of nanoadsorbent. Furthermore, spectrophotometric determinations for dye were done at λ = 265 nm and the results show the linearity in the range of 1.0-50 μg mL− 1.