▎ 摘　　要

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 recollected 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.