Abstract
Multi-walled carbon nanotubes (MWCNTs) coated with magnetic Co1-xZnxFe2O4 nanoparticles (x = 0.0–1.0) were prepared via novel gelatin method. The synthesized nano-composites were characterized using X-ray diffraction, Fourier transform infrared (FT-IR) and transmission electron microscopy (TEM) to clarify the nano-composites formation and discuss the coating mechanism. The effect of the ferrite presence along with Zn-substitution on thermal stability, magnetic and conductivity characteristics was investigated and discussed. The addition of CoFe2O4 obviously decreases stability through catalyzing MWCNTs oxidative decomposition while increasing Zn-content inhibit it. The changes in the magnetization values by Zn addition was discussed in the view of changing cation distribution. All the investigated nano-composites exhibited metallic conduction characteristic of MWCNTs without any indication for any changes with Zn-substitution. The magnetic sensitivity along with high surface area exhibited by the entire nano-composites enhanced their use in adsorption removal of acid red (AR) toxic dye from aqueous solutions. In this category, the nano-composites with x = 0.0, 0.4 and 0.8 were examined to study the efficiency of the adsorption process and to investigate the effect of Zn-content on the adsorption. The effect of various parameters including pH, contact time, temperature and mass on the removal efficiency was also studied. In addition, the kinetic as well as the thermodynamic parameters were investigated and discussed.
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•Co1-xZnxFe2O4/MWCNTs nano-composites were prepared via novel gelatin auto-combustion method.•The decoration process was fully characterized and discussed.•The effect of zinc on thermal stability, magnetic and conductivity of MWCNTs was investigated.•The nano-composite was examined to remove acid red (AR) dye from aqueous media.•The optimum condition for removal, kinetics and thermodynamic was investigated and discussed.