Dihalogen Cross linked Fe3O4-Reduced Graphene Oxide Nanocomposites for Arsenic and Mercury Adsorption

Graphene oxide was synthesized by Hummers method and then reduced with hydrazine hydrate to obtain reduced graphene oxide. Dihalogen crosslinked Fe3O4 core shell nanoparticles (DCSNs) were synthesized by crosslinking amine functionalized Fe3O4@SiO2 core-shell nanoparticles with 1,2-bromochloroethane. These nanoparticles were then loaded on to the reduced graphene oxide to obtain reduced graphene oxide-nanocomposites (RGO-NC). The nanocomposites were characterized using FT-IR, Raman, N-2 sorption, VSM, SEM and TEM. The surface area was found to be 388 m(2)/g due to crosslinking of amine functionalized Fe3O4@SiO2 core shell nanoparticles with 1,2-bromochloroethane. The saturation magnetization of RGO-NC (17.1 emu/g) was sufficient to remove the nanocomposites from aqueous solution. The nanocomposites were used as adsorbent for the removal of arsenic and mercury in water. The maximum adsorption capacity for As(V) at pH 6 was found to be 45.5 mg/g, whereas at neutral pH the adsorption capacity for As(III) and Hg(II) was 62.7 and 81.3 mg/g respectively. The adsorption capacity of arsenic and mercury was slightly affected by the coexistence of other anions and cations.