Ultrasonication-assisted green synthesis of graphene by nickel powder reduction

A new method was presented to effectively reduce graphite oxide to graphene with nickel powder at room temperature. The reduced graphite oxide was characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the oxygen functionalities of the graphite oxide were mostly removed, and the intensity ratio (I_D/I_G) of D band to G band of reduced GO (rGO) is about 1.34. When the mass ratio of Ni and GO is 2, the effect of reduction is relative ideal. This method offers a feasibility for low-cost, effective, environmentally friendly and large-scale production of graphene.