Functionalized Fe3O4@C Nanospheres with Adjustable Structure for Efficient Hexavalent Chromium Removal
journal contributionposted on 04.10.2017, 00:00 by Linglin Zhou, Guilong Zhang, Jie Tian, Dongfang Wang, Dongqing Cai, Zhengyan Wu
Core–shell magnetic Fe3O4@C nanospheres functionalized with active chemical groups were synthesized via a one-step template-free solvothermal process and employed to remove hexavalent chromium (Cr(VI)) in aqueous media. The structure of Fe3O4@C nanoparticles could be effectively adjusted by the concentration of precursor. The Fe3O4 core possessed a high magnetism for the convenient separation of Fe3O4@C from aqueous solution, and high porosity and abundant functional groups (−OH, −COOH, and CC) of carbon layer contributed to a superior performance on Cr(VI) removal. Therein, Cr(VI) ions could be efficiently adsorbed into the carbon layer and reduced to trivalent chromium (Cr(III)) mainly by CC, and the resulting Cr(III) were chelated by the −COOH group. Noteworthy, the carbon layer thickness, pore size, and amount of chemical groups significantly increased with the increase of Fe3O4@C particle size resulting in a rising removal efficiency on Cr(VI). This study provides a promising approach for removing Cr(VI) and may have a huge application potential.