Eco-friendly one-pot synthesis of gold decorated reduced graphene oxide using beer as a reducing agent

• Green, easy method was demonstrated for synthesis of Au decorated graphene composite.
• Beer used as a reducing agent for the synthesis of gold decorated graphene.
• Microscopic analysis show good dispersion of Au nanoparticles on graphene surface.
• Composite demonstrates high electrocatalytic activity towards oxygen.

A facile, eco-friendly and economical approach was demonstrated for the synthesis of gold-decorated reduced graphene oxide nanocomposites (rGO–Aunano) 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–Aunano 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–Aunano/GCE was much lower than that of the GCE and GO/GCE. The proposed nanocomposites have excellent electrocatalytical properties for catalytic reduction of O2 in solution.