▎ 摘　　要

Herein, a novel Pt-APA composite (APA = pyridinium bromide salt) based on magnetic graphene oxide was synthesized and used as an effective catalyst. In this way, Fe3O4 nanoparticles are grown on graphene oxide (GO) nanosheets by a simple and practical method which creates a unique nanostructure (Fe3O4/GO) through dispersing uniformly among graphene nanosheets. The resulted Pt-APA composite was obtained via adding PtCl2 to an ethanol solution of Fe3O4/GO and alpha-keto stabilized pyridinium ylide in related conditions. The synthesized nanocomposite structure was identified using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectral analysis (EDS), inductively coupled plasma spectrometry (ICP-MS), powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), vibrating-sample magnetometer (VSM), and UV - Vis spectroscopy. To investigate the catalytic properties of the synthesized Pt-APA@Fe3O4/GO nanocomposite, it was firstly used as an efficient nano-magnetic catalyst in C-C cross-coupling reaction, Suzuki-Miyaura, with excellent results. Second, the Pt-APA@Fe3O4/GO nanocomposite has been used as a magnetic photocatalyst to inactivate E. coli bacteria on a nutrient agar plate under visible light irradiation, which showed excellent results. By examining the results, the antibacterial durability of nanocomposites Pt-APA@GO/Fe3O4 related to Fe3O4/GO shows a more significant inhibition against bacteria cell in both dark and visible light.