Graphene oxide--magnetite nanocomposite as an efficient and magnetically separable adsorbent for methylene blue removal from aqueous solution


Abstract: We report a facile method to produce a magnetically separable graphene oxide--magnetite nanocomposite (GO--Fe_3O_4) and its adsorption performance in methylene blue (MB) removal from aqueous solution. The GO--Fe_3O_4 nanocomposite was synthesized by a solution-phase self-assembly method including the incorporation of monodisperse Fe_3O_4 nanoparticles (NPs) and GO in a dimethylformamide/chloroform mixture under sonication. The successfully decorating GO sheet with monodisperse Fe_3O_4 NPs was proved by TEM study. ICP--OES data of the GO--Fe_3O_4 nanocomposite show that the GO--Fe_3O_4 nanocomposite consists of 21 wt% Fe_3O_4 NPs, which is sufficient for its magnetic separation from aqueous solution. The spectroscopic studies reveal that the GO--Fe_3O_4 nanocomposite is a highly efficient adsorbent for MB removal from aqueous solution, providing an adsorption capacity of 172.6 mg/g, and the equilibrium for MB adsorption is attained in \sim 70 min. Moreover, it is a magnetically separable and reusable material for MB removal from water, preserving 87% of its initial efficiency after 5 successive runs.

Keywords: Graphene oxide, Fe_3O_4 nanoparticles, composite sorbent, magnetic separation, dye removal, methylene blue

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