Preparation of FeS@Fe3O4 core-shell magnetic nanoparticles and their application in uranyl ions removal from aqueous solution

FeS@Fe3O4 magnetic nanoparticles were prepared by ultrasonic-assisted method and characterized by TEM, FTIR, XRD, SEM, EDS, BET and VSM. The factors affecting the adsorption properties of uranyl ions by FeS@Fe3O4 were studied. Results show that the FeS@Fe3O4 nanoparticles have core-shell structure and superparamagnetism. Under the optimized conditions, the maximum adsorption capacity can reach 229.03mg/g. The optimum adsorption conditions were as follows: pH=6, temperature 80 degrees C, C-0=35mg/L, contact time 2.5h, adsorbent dosage 10mg. Adsorption kinetics and thermodynamic studies show that the adsorption process accords with the Freundlich isotherm adsorption model and the pseudo-second-order kinetic model.