Synthesis of magnetic chrysotile nanotubes for adsorption of Pb(II), Cd(II) and Cr(III) ions from aqueous solution

• Magnetic chrysotile nanotubes were synthesized under hydrothermal conditions.
• The products have preferable saturation magnetization (12.78 A m2 kg−1).
• Adsorption behavior had been studied for the Pb(II), Cd(II) and Cr(III).
• The products remain higher adsorption capacity toward heavy metal ions than ChNTs.

In view of increasing attention of magnetic materials in the field of separation science and technology, we prepared a kind of magnetic material (magnetic chrysotile nanotubes, viz., magnetic ChNTs) by the doped method. Different experimental conditions were studied using different characterization analysis. The characterization results showed that the prepared samples had hollow structure and preferable saturation magnetization. Magnetic ChNTs could be effectively separated from aqueous solutions by a permanent magnet. The adsorption kinetics and isotherms of magnetic ChNTs for Pb(II), Cd(II) and Cr(III) were fitted well by the pseudo-second-order model and Langmuir model, respectively. The possible adsorption mechanism was discussed mainly according to characterizations (FTIR, XPS) and experiments, which together suggested that Pb(II), Cd(II) and Cr(III) adsorption on magnetic ChNTs most possibly involved electrostatic interaction and surface complexation.