A highly efficient catalyst: In situ growth of Au nanoparticles on graphene oxide–Fe3O4 nanocomposite support

• In situ growth of Au NPs with magnetic graphene oxide as support was developed.
• The nanocomposite shows enhanced catalytic efficiency for reduction of 4-NP.
• The novel catalyst can be used for 10 cycles and stored for at least one month.
• GOFe3O4 is an excellent support and in situ growth makes the catalyst more stable.

In this paper, a simple and green route for in situ growth of Au shell or grown Au NPs attached on the graphene oxide–iron oxide nanocomposite (GOFe3O4) was established. After functionalized with amino groups, the GOFe3O4 nanocomposites can adsorb negatively charged Au nanoparticles (Au NPs) which acted as gold seeds. Then the HAuCl4 solution provides gold precursor with glucose serving as reducing reagent, whereby the crystal growth leads to the in situ growth of Au shell or grown Au NPs attached on the surface of GOFe3O4, and a highly efficient catalyst denoted as GOFe3O4Au NPs(G) was obtained. The prepared nanocomposites were characterized and their catalytic activity was evaluated using the reduction of 4-nitrophenol (4-NP) as a model reaction. It shows that the GOFe3O4Au NPs(G) possess high catalytic performance for reduction of 4-NP with conversion rate of 100% within 100 s. Furthermore, the new catalyst can be stored for more than one month, easily recovered and reused at least for ten cycles. Comparing with the nanocomposites without crystal growth, the formation of Au shell or Au NPs attachment on the support via in situ growth approach not only apparently improves catalytic activity, recyclability but also increases their stability.

A highly efficient GOFe3O4/Au NPs(G) catalyst was synthesized by in situ growth method and used for reduction of 4-nitrophenol.Figure optionsDownload as PowerPoint slide