Sulfonic Acid Functionalized Magnetite Nanoporous-KIT-6 for Removal of Methyl Green from Aqueous Solutions

The sulfonic acid-functionalized KIT-6 magnetite mesoporous silica nanoparticles (Fe3O4@SiO2@KIT-6-SO3H NPs) were prepared as an adsorbent and used for the removal of methyl green from aqueous solutions. Characterization of the obtained adsorbent was done by FT-IR, SEM and EDX instruments. According to the experimental results, about 96.4 % of dye was removed from aqueous solutions at the adsorbent amount of 3.2 g L-1 at pH = 3 and ionic strength = 0 during 10 min. The kinetic results indicated that the pseudo-second-order kinetic model was the best model for describing the adsorption kinetic (R-2 = 0.9999). The isotherm analysis demonstrated that the equilibrium data were well fitted to the Freundlich isotherm model, showing a multilayer adsorption of the dye on the adsorbent surface. The maximum adsorption capacity for methyl green was obtained 196 mg g(-1). Furthermore, the Fe3O4@SiO2-KIT-6-SO3H NPs could be simply recovered by external magnet and it exhibited recyclability and reusability for six cycles. The results showed that the Fe3O4@SiO2-KIT-6-SO3H NPs are appropriate adsorbent for removal of methyl green from real wastewater samples.