Synthesis and characterization of MgO supported Fe–Co–Mn nanoparticles with exceptionally high adsorption capacity for Rhodamine B dye

摘要

In this work, MgO supported Fe–Co–Mn nanoparticles (MgO-FCM-NPs) are synthesized and utilized as adsorbent for the successful removal of Rhodamine B dye (RhB) from aqueous environments. In the first step, the synthesized MgO-FCM-NPs are identified using scanning electron microscopy (SEM), vibration sample magnetization (VSM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) techniques. In the second step, the effects of different adsorption conditions such as solution pH (3–13), dye concentration (10–120?mg?L?1), adsorbent dosage (0.04–0.12?g?L?1), temperature (298–318?K) and contact time (20–100?min) are investigated. The pH 7 is found to be the optimized pH and the equilibrium is reached in 60?min for RhB adsorption onto MgO-FCM-NPs. The maximum adsorption capacity of RhB onto MgO-FCM-NPs is found to 1106?mg?g?1at pH 7, temperature 318?K and contact time 60?min using 120?mg?L?1RhB concentration. The adsorption data is fitted better to Langmuir isotherm model (R2?=?0.999) in comparison to Freundlich and Temkin equilibrium isotherm models. The n (Freundlich constant) values are in between 1–10, suggesting desirable adsorption of RhB onto MgO-FCM-NPs. Further the adsorption process of RhB onto MgO-FCM-NPs is followed pseudo-second-order kinetics (R2?=?0.9999). The negative values of Gibbs free energy (ΔG°) represents spontaneity of the process and the positive values of enthalpy (ΔH°) of RhB adsorption onto MgO-FCM-NPs indicates the endothermic nature. Finally, it is concluded that the MgO-FCM-NPs could be used for effective RhB removal from textile effluents.