Adsorption property of Cr(vi) on magnetic mesoporous titanium dioxide–graphene oxide core–shell microspheres

Abstract

Novel Fe3O4@mTiO2@GO microspheres for the fast removal of Cr(VI) were synthesized by immobilizing a mesoporous TiO2 shell on the surface of magnetic Fe3O4 nanoparticles prior to binding with GO. The characterization results from FTIR, SEM, VSM and XRD showed that Fe3O4@mTiO2@GO was successfully prepared with a large surface area and good magnetic responsiveness. It was shown that the sorption of the microspheres for Cr(VI) was strongly dependent on pH value and contact time. As Cr-removal adsorbents, the maximum Cr-removal capability of microspheres was 117.94 mg g−1. The equilibrium adsorptions were well-described by the Freundlich isotherm mode and its kinetics followed pseudo-second-order rate equation. Moreover, the Fe3O4@mTiO2@GO microspheres could be regenerated and used repeatedly by simple treatment without obvious structure and performance degradation. These results demonstrated the potential applications of Fe3O4@mTiO2@GO microspheres in the efficient Cr-removal from wastewater and purification of polluted water.