Reduced graphene oxide wrapped Fe3O4-Co3O4 yolk-shell nanostructures for advanced catalytic oxidation based on sulfate radicals

In this work, we designed and synthesized a high performance catalyst of reduced graphene oxide ( RGO) wrapped Fe3O4-Co3O4 ( RGO/Fe3O4-Co3O4) yolk-shell nanostructures for advanced catalytic oxidation based on sulfate radicals. The synergistic catalytic action of the RGO/Fe3O4-Co3O4 yolk-shell nanostructures activate the peroxymonosulfate ( PMS) to produce sulfate radicals ( SO4 center dot-) for organic dyes degradation, and the Orange II can be almost completely degradated in 5 min. Meanwhile the RGO wrapping prevents the loss of cobalt in the catalytic process, and the RGO/Fe3O4-Co3O4 can be recycled after catalyzed reaction due to the presence of magnetic iron core. What's more, it can maintain almost the same high catalytic activity even after 10 cycles through repeated NaBH4 reduction treatment. Hence, RGO/Fe3O4-Co3O4 yolk-shell nanostructures possess a great opportunity to become a promising candidate for waste water treatment in industry. (C) 2016 Elsevier B. V. All rights reserved.