Magnetic response and adsorptive properties for methylene blue of CoFe2O4/CoxFey/activated carbon magnetic composites

Owing to the unique microporous structure and high surface area, activated carbon (AC) was a good adsorbent in the environmental protection filed. In this paper, CoFe2O4 and CoxFey were anchored into AC to synthesize CoFe2O4/CoxFey/AC composites by sol-gel method. The microstructures and magnetic properties of CoFe2O4/CoxFey/AC were discussed by XRD, TGA, ASAP and VSM. The results indicated that CoFe2O4 and CoxFey nanoparticles existed in the pores of AC. The saturation magnetization (Ms) of CoFe2O4/CoxFey/AC composites increased with CoFe2O4 and CoxFey, while the surface area and pore volume decreased. The S-200 sample (Co:Fe:C = 1:2:200) possessed the surface area of 967.17 m(2) g(-1) and Ms of 9.44 emu/g, which was sufficient for the application in wastewater treatment. Furthermore, the kinetic studies indicated that adsorption process for methylene blue (MB) conformed to the Langmuir model. 99% MB could be adsorbed in 50 min, and CoFe2O4/CoxFey/AC composites could be separated easily by magnetic separation technique. (C) 2014 Elsevier B.V. All rights reserved.