Fenton-Like Degradation of Acid Orange 7 Using Graphene Oxide-Iron Oxide Nanocomposite

Abstract

This work presents a facile, scalable method for the fabrication of graphene oxide-iron oxide (GO-FeO) nanocomposites produced by co-precipitation of iron ions onto the GO surfaces in basic aqueous media. FTIR and XRD characterisation suggests that FeO was chemically anchored to the GO sheets, possibly via the carboxyl and hydroxyl groups. Small GO loadings of 0.5 and 1 wt% were not sufficient to alter the FeO structures. However, increasing the GO loading to 5 and 10 wt% resulted in significant loss in pore volume, thus suggesting the lamellar GO sheets decorated with FeO were assembling into GO-FeO nanocomposite stacks. It was found that the GO-FeO nanocomposites had an enhanced catalytic activity in the heterogeneous Fenton-like oxidation of Acid Orange 7 (AO7) compared to pure GO flat sheets and FeO nanoparticles. Interestingly, the GO-FeO nanocomposite with 5 wt% loading ratio exhibited the best catalytic activity with 76% degradation of AO7 dye observed within 90 min of reaction. This was attributed to the synergistic effect of GO by enriching the adsorbed AO7 molecules onto the nanocomposite to be further oxidised in the vicinities of active sites. This finding suggests the promising employment of GO-FeO nanocomposites in removing organic dyes from polluted water by heterogeneous Fenton-like reaction.