Plasma-induced grafting of cyclodextrin onto multiwall carbon nanotube/iron oxides for adsorbent application

The magnetic composite of beta-cyclodextrin grafted onto multiwalled carbon nanotubes/iron oxides (denoted as MWCNTs/iron oxides/CD) was synthesized using the plasma-induced grafting technique and was developed for the removal of inorganic and organic pollutants from aqueous solutions. The characteristic results of Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), and thermogravimetric analysis (TGA) showed that beta-CD was grafted onto the MWCNTs/iron oxides. The grafted beta-CD on the MWCNTs/iron oxides contributed to an enhancement of the adsorption capacity because of the strong abilities of the multiple hydroxyl groups and the inner cores of the hydrophobic cavity in beta-CD to form complexes with metal ions and organic pollutants. MWCNTs/iron oxides/CD can be separated and recovered from solution by magnetic separation. The adsorption of Pb(II) on MWCNTs/iron oxides/CD was found to be dependent on pH, and the adsorption of 1-naphthol was found to be independent of pH. The results show that the magnetic composite of MWCNTs/iron oxides/CD is a promising composite material for the preconcentration and separation of inorganic and organic pollutants from aqueous solutions in environmental pollution cleanup.