In situ preparation of magnetic Ni-Au/graphene nanocomposites with electron-enhanced catalytic performance

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.