Decoration of MWCNTs with CoFe2O4 Nanoparticles for Methylene Blue Dye Adsorption

In the present work, a simple and viable method for producing multi-walled carbon nanotubes (MWCNTs) decorated with CoFe2O4 nanoparticles is presented. Chemical composition and crystal structure of the CoFe2O4/MWCNT composite was confirmed by X-ray diffraction measurements, while transmission electron microscopy was used to characterize the morphology and the distribution of nanocrystals in the composite. The obtained particles with relatively small diameter (about 14.9 nm) were found to be dispersed on the carbon nanotubes. The adsorption of methylene blue dye on CoFe2O4/MWCNT composites has been investigated. CoFe2O4/MWCNT composites show high adsorption capacity for methylene blue dye. Both Langmuir and Freundlich models describe the adsorption isotherms very well and the adsorption thermodynamic parameters (∆G0, ∆H0 and ∆S0) were calculated. The adsorption of methylene blue is generally spontaneous and thermodynamically favorable. The adsorption of methylene blue involves an endothermic process.