Synthesis and adsorption characteristics of pudding-like Fe/C magnetic composites for methylene blue removal

Abstract

Pudding-like Fe/C materials were successfully synthesized via an emulsion cross-linking method followed by a heat-treatment process. The morphologies and compositions can be easily controlled via adjusting the heat-treatment temperature. XRD, SEM, TEM, XPS, VSM, BET surface area measurements and zeta potential analysis were used to characterize the as-prepared samples. The adsorption capacity of MB (methylene blue) was systematically studied in different initial concentrations and pH of MB solution and at ambient temperature. Kinetics and isotherm synthesis were fitted well with the model of pseudo-second-order and Langmuir isotherms, respectively. The pudding-like Fe/C composites exhibited excellent adsorption performance in the removal of MB and the maximum adsorption capacity was 243.9 mg g⁻¹, which was obtained for a 100 mg L⁻¹ of MB solution at pH 7.0 and 25 °C. After ten cycles of adsorption experiments, the adsorption capacity can be maintained at about 93%, which indicated that the pudding-like Fe/C exhibited excellent adsorption stability and reusability.