▎ 摘　　要

A new type of microflowers composed of Fe3O4, reduced graphene oxide (RGO), and Ag nanoparticles (Ag NPs) was prepared by using an electrostatic self-assembly technique followed by a one-step reduction of graphite oxide and Ag+. The as-prepared composite microflowers (Fe3O4/RGO/Ag NPs) were characterized with power X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. Meanwhile, the catalytic activity of Fe3O4/RGO/Ag NPs was studied using Rhodamine B (RhB) as a degradation substrate and NaBH4 as a reducing agent. The results indicated that the catalytic activity of Fe3O4/RGO/Ag NPs was excellent, and the degradation efficiency was up to 100% within 4 min when the loading amounts of RGO and Ag NPs were only about 1% and 1.5%, respectively. The enhanced catalytic activity of the microflowers was attributed to the synergistic effect of RGO and Ag NPs. Moreover, the catalyst can be easily recovered by using a magnet. The Fe3O4/RGO/Ag NP microflowers could be used as a high-efficiency catalyst for the degradation of hazardous dyes in wastewater. (C) 2014 Elsevier Ltd. All rights reserved.