A facile and rapid removal of cationic dyes using hierarchically porous reduced graphene oxide decorated with manganese ferrite

Herein, MnFe2O4/reduced graphene oxide nanoparticles (MrGO) were synthesized for the effective removal of various cationic dyes. The synthesized nanocomposites exhibited high adsorption capacity for removing cationic dyes as malachite green dye MG and methylene blue dye MB reaching 156, and 105 mg/g at 30 ?C, respectively. The high surface area of the prepared adsorbent, 95 m2/g, electrostatic interaction, and ?-? interaction facilitated dyes removal on MnFe2O4/rGO. The physicochemical properties of the synthesized hybrid nanocomposite were investigated using FESEM, XRD, VSM, HRTEM, and N2-adsorption/desorption isotherms. The influence of contact time, adsorbent dose, initial dye concentration, pH, rate of agitation, and change in temperature were investigated. Various adsorption isotherms equations were applied to give a clear concept on the mechanism of the dye removal process and the results indicated that dyes removal followed both Freundlich and Langmuir models. Kinetics results pointed out that the removal fitted well to pseudo-second-order. The thermodynamic parameters showed that the removal process was endothermic and spontaneous. The synthesized adsorbent showed high stability after reuse for five cycles.