Multifunctional Magnetic Graphene Nanocomposites for Environmental Remediation

A one-pot synthesis method to obtain multifunctional graphene nanocomposites decorated with monodispersed core@double-shell nanoparticles is developed in this work. High-resolution transmission electron microscopy and energy filtered elemental mapping revealed a core@double-shell structure of the nanoparticles with the core and inner shell being crystalline iron and iron oxide, and the outer shell of amorphous Si-S-O compound. These magnetic graphene nanocomposites show an extremely fast chromium (VI) removal efficiency (completely removed in 5 min) from the waste water and a significantly high adsorption capacity (20.9 mg/g from 10 wt% nanoparticle loading). This material shows great advantages as compared to traditional adsorbents, such as active carbon, biomass, iron oxide that often require hours even days to remove the heavy metal ions.