Porous graphene oxide based inverse spinel nickel ferrite nanocomposites for the enhanced adsorption removal of arsenic

Abstract

Porous graphene oxide based magnetic inverse spinel nickel ferrite nanocomposites, namely graphene oxide based inverse spinel nickel ferrite (GONF) and reduced graphene oxide based inverse spinel nickel ferrite (rGONF), with particle sizes of around 30 to 40 nm were prepared by the co-precipitation of graphene oxide (GO) with nickel and iron salts in one pot. GONF and rGONF, having ferromagnetic and superparamagnetic properties respectively, were separated easily within 10 seconds, using a small external magnetic field. These nanocomposites were used for the adsorption removal of As(III) and As(V). Compared to bare nickel ferrite, other nanocomposites and GO, the nanocomposites show a high adsorption capacity for As(III) and As(V), with considerable enhancement. The enhanced high adsorption capacity is due to the increased number of pores and adsorption sites with increasing surface area in the GONF and rGONF composites, through reducing the aggregation of bare ferrites. The adsorption results found that more than 99.9% arsenic removal was achieved with the present nanocomposites. Since the nanocomposites show good stability without loss of their adsorption capacity for up to 5 cycles, they can be used for the practical removal of arsenic from water.