▎ 摘　　要

Design supported bimetallic nanoparticles is an interesting and important strategy for developing new catalysts with enhanced activity and selectivity. Herein the magnetically separable reduced graphene oxide supported Ni-Au (RGO-Ni-Au) nanocatalysts were prepared by an in situ co-reduction and surfactant-free method, which exhibited excellent performance both in the catalytic reduction of 4-nitrophenol and degradation of environmentally polluting dyes with NaBH4. The best activity parameters of RGO-Ni-Au-6h nanocomposites for 4-nitrophenol reduction is 36.77 s(-1) g(-1) with an apparent rate constant of 11.03 x 10(-3) s(-1). Additionally, the prepared catalyst could be recycled over 6 times without obvious performance decay or even a morphology change. The enhancement in catalytic capability can be ascribed to the electron-enhanced effect of graphene support and strong synergistic effect between noble metal and magnetic transition metal. It is believed that such desirable catalyst with magnetic properties, high activity, and long-life stability make it promising in retrievable catalysis. (C) 2017 Elsevier B.V. All rights reserved.