▎ 摘　　要

A facile, eco-friendly and economical approach was demonstrated for the synthesis of gold-decorated reduced graphene oxide nanocomposites (rGO-Au-nano) using beer as a reducing agent via a hydrothermal method. The phenolic compounds of beer play a key role in the reduction of graphene oxide and the gold precursor. The obtained rGO-Au-nano was characterized by X-ray diffraction, UV-vis absorption spectroscopy, electron microscopy, atomic force microscopy and the electrochemical impedance spectroscopy. Analysis revealed that the electron-transfer resistance of rGO-Au-nano/GCE was much lower than that of the GCE and GO/GCE. The proposed nanocomposites have excellent electrocatalytical properties for catalytic reduction of O-2 in solution. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.