Structural, morphological and magnetic properties investigation of magnetically separable mesoporous carbon

This paper reports on the preparation of nanocomposites containing mesoporous carbon with different molar ratios of Ni or CoFe2O4 nanoparticles as magnetically separable absorbents by facile, reproducible and economical processes including self-assembly soft template hydrothermal route and Pechini-type sol-gel techniques. Accordingly, structural, morphological and magnetic properties of the samples were studied using XRD, FT-IR, FE-SEM, HR-TEM, N2 adsorption-desorption and VSM methods. Based on the VSM results, two different types of magnetic behavior were observed. Composites containing nickel had typical S-shaped hysteresis curves with a very low coercivity (Hc ≈ 84, 97 Oe) and retentivity (Mr ≈ 1.1, 2.4 emu/g), as compared to their relatively high saturation magnetization value (Ms ≈ 3.9, 8.6 emu/g), while the other samples were ferromagnetic. The M − H curves have also revealed that saturation and remnant magnetization, as well as coercivity, were increased by enhancing the magnetic phase content in all nanocomposites. Also, the MC-Ni/CFO nanocomposites performance as the magnetically separable adsorbents for vitamin B12 adsorption was evaluated. The MC-5CFO adsorbent illustrated higher adsorption capacity (325.66 mg/g) than MC-2Ni (139.25 mg/g) in 250 ppm due to the higher BET surface area (589 m2/g) and pore volume (0.71 cm3/g).