Oxygenated functionalities enriched MWCNTs decorated with silica coated spinel ferrite ? A nanocomposite for potentially rapid and efficient de-colorization of aquatic environment

Abstract

Herein, a novel silica coated copper ferrite decorated oxidized multi-walled carbon nanotubes (CuFe2O4/oMWCNTs) nanocomposite was synthesized through co-precipitation and hydrothermal reactions and was used for the adsorptive removal of cationic methylene blue (MB) and celestine blue (CB) dyes from water. Nitrogen adsorption/desorption isotherm confirmed mesoporous nanocomposite surface with 182 m2/g specific surface area. Spectral bands observed during IR analysis confirmed successful formation of nanocomposite. The VSM analysis revealed its ferromagnetic behavior with 0.004 emu/g saturation magnetization. Binding energy peaks observed during XPS analysis further supported nanocomposite synthesis and dyes adsorption over its surface. Dyes adsorption was observed to be affected by pH and temperature with equilibrium and kinetic results respectively fitting the Langmuir isotherm and the pseudo-second-order models. Maximum monolayer adsorption capacities determined for CB and MB adsorption on nanocomposite were 714 mg/g (293 K) and 204 mg/g (323 K), respectively. Regeneration studies revealed maximum CB and MB recovery with acetonitrile (ACN) and methanol (MeOH), respectively. Therefore, the novel CuFe2O4/oMWCNTs nanocomposite here synthesized is a suitable adsorbent for rapid and effective decolorization of cationic dyes containing wastewaters.