▎ 摘　　要

A facile method for preparing Ni-Ag bimetallic nanoparticles supported on reduced graphene oxide (Ni-Ag@RGO hybrid) has been established. Hydrazine hydrate was used as the reducing agent to reduce the graphene oxide, Ni2+ and Ag+ to form Ni-Ag@RGO hybrid. The prepared hybrid was further characterized by X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, and transmission electron microscopy. Interestingly, the prepared material shown good magnetic properties, which were determined by vibrating sample magnetometer. In addition, the Ni-Ag@RGO hybrid exhibited excellent catalytic activity for the reduction of 4-nitrophenol and the photodegradation of methyl orange. The catalytic process was monitored by determining the change in the concentration of the reactants with time using ultraviolet-visible absorption spectroscopy. After completion of the reaction, the catalyst can be separated from the reaction system simply under a magnet field and shows good recyclability. (C) 2015 Elsevier B.V. All rights reserved.