Iron oxide impregnated mesoporous MCM-41: synthesis, characterization and adsorption studies

Mesoporous MCM-41 and MCM-41 impregnated with structural iron (Fe–MCM-41) were prepared by a facile surfactant based wet chemical method using tetraethyl orthosilicate, cetyl trimethyl ammonium bromide in the presence of ammonium hydroxide and FeSO4·7H2O as impregnated reagent. The prepared mesoporous materials were characterized by small and wide angle X-ray diffraction (XRD), XPS, FESEM, HRTEM, FTIR and N2 gas adsorption/desorption isotherm techniques. The results indicate the formation of high surface area (1266 m2/g) porous structure with particle size in the range of 200–400 nm for MCM-41. In case of Fe–MCM-41 the surface area decreases (880 m2/g) substantially with formation of iron oxide nanoparticles in the frame work of MCM-41. The obtained mesoporous materials were used as adsorbents for the removal of methylene blue from aqueous media. The percentage removal of the dye was found to be 99.9% for Fe–MCM-41 and 94.5% for MCM-41, respectively, by using 20 mL of dye solution with initial concentration of 100 mg/L and 0.05 g of each adsorbent. The maximum adsorption capacity of Fe–MCM-41 was found to be 194 mg/g and for MCM-41, it was 149.5 mg/g. This result suggests that the prepared Fe–MCM-41 is an effective adsorbent for decontamination of Methylene blue from aqueous media.