Ultrasonication-assisted ultrafast reduction of graphene oxide by zinc powder at room temperature

A green method is reported to effectively and rapidly reduce graphene oxide to graphene with zinc powder at room temperature. The reduction is carried out by mixing graphene oxide and zinc powder in solution under ultrasonication. The reduction is complete within 1 min. The weight of the Zn powder should be at least as twice as that of graphene oxide to complete the reduction. The reduction of graphene oxide is confirmed by FTIR, UV–Vis absorption spectroscopy and Raman spectroscopy. The carbon/oxygen atomic ratio has increased from 2.58 to 33.5 after the reduction as determined by X-ray photoelectron spectroscopy. The reduced graphene oxide can have a conductivity of 15,000 S/m. It also has good thermal stability with the weight loss at 590 °C in air. The reduced graphene oxide can be readily re-dispersed into solutions of various surfactants.