Synthesis and characterization of a novel SnFe2O4@activated carbon magnetic nanocomposite and its effectiveness in the removal of crystal violet from aqueous solution

• Outline of preparation and characterization of a novel SnFe2O4@activated carbon magnetic nanocomposite.
• SnFe2O4@activated carbon magnetic nanocomposite is used for the removal of crystal violet.
• Adsorption isotherms, kinetics, and thermodynamic parameter have been studied.
• Results showed good potential of magnetic nanocomposite for the removal of crystal violet.
• Magnetic nanocomposite exhibits good reusability.

In the present study, SnFe2O4@activated carbon magnetic nanocomposite was synthesized via co-precipitation route. The as-prepared magnetic nanocomposite was characterized by BET surface area analyzer, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), vibrating sample magnetometer (VSM), and through the determination of pHzpc. The performance of magnetic nanocomposite was further evaluated for its potential in adsorptive removal of cationic dye, crystal violet (CV). The effect of various parameters such as initial dye concentration, contact time, pH, and temperature were also investigated. The adsorption equilibrium data were analyzed by Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models and Langmuir model found to be the most appropriate one. The maximum sorption capacity for the removal of CV was calculated as 158.73 mg/g at 323 K. The adsorption kinetics was analyzed using pseudo-first order, pseudo-second order, and intra-particles diffusion models. Adsorption kinetics reveals better agreement with pseudo-second order model. Investigation of thermodynamic parameters suggests endothermic and spontaneous nature of dye removal process. All these results revealed that the as-prepared magnetic nanocomposite has a remarkable potential for the removal of CV from aqueous solution.