MWCNTs decorated Mn0.8Zn0.2Fe2O4: Synthesis, characterization and compositional effect on the structural and magnetic properties

In the present study, Mn0.8Zn0.2Fe2O4 nanoparticles, synthesized from spent Zn-C batteries extract, were successfully used for decoration of multi-walled carbon nanotubes (MWCNTs). This MWCNTs/Mn0.8Zn0.2Fe2O4 magnetic nano-composites were prepared by the addition of MWCNTs during the preparation of the entire ferrite using sucrose combustion method. The effect of MWCNTs content (0-70%) on the structural, morphological and magnetic properties of entire ferrite was investigated and discussed. The results showed that high purity Mn0.8Zn0.2Fe2O4 nano-crystallites were completely decorated on the sidewalls of the MWCNTs up to 30% content and the decoration behavior, shape and density are dependent on the composition. The saturation magnetization was observed to decrease with increasing MWCNTs content while coercivity showed a particle size dependent behavior. The composition with 70% MWCNTs was examined as adsorbent for methylene blue dye (MB) from aqueous media based on its relatively high surface area and the capability of removing the nano-composite after adsorption process using normal magnet. The nano-composite showed a very high adsorption capacity and the kinetic as well as the thermodynamics of adsorption/removal process were investigated and discussed. Repeated testing showed the applicability of the nano-composite for the removal of MB from aqueous solution frequently with acceptable efficiencies.