ZnNi alloy nanoparticles grown on reduced graphene oxide nanosheets and their magnetic and catalytic properties

Abstract

Reduced graphene oxide (RGO)–ZnNi alloys nanocomposites were synthesized by in situ growth of ZnNi alloy nanocrystals on graphene oxide (GO) accompanied with a chemical co-reduction process. The size and morphology of ZnNi alloy nanoparticles on RGO sheets can be tuned by simply changing initial concentrations of metal ions and molar ratio of Zn²⁺ to Ni²⁺ in the reaction system. The as-synthesized products were characterized by powder X-ray diffraction, energy dispersive X-ray spectroscopy, Raman spectroscopy and transmission electron microscopy. Magnetic measurements reveal that the nanocomposites have ferromagnetic characteristics and show composition dependent magnetic properties. Moreover, the RGO–ZnNi nanocomposites show remarkably enhanced catalytic activity and recycling stabilities toward the reduction of 4-nitrophenol (4-NP), and can be easily re-collected from the reaction system by a magnet. It is believed that the obtained magnetic RGO–ZnNi nanocomposites with excellent catalytic properties provide a new opportunity for the application of graphene-based materials.