Effect of stirring on characteristics of electrochemically exfoliated graphene

Electrochemical exfoliation of graphite is a promising technique for the synthesis of graphene at a commercial scale. Electrochemical synthesis of graphene at high voltage (similar to 10 V) is widely reported. However, at high voltage, multilayer graphene platelets with high defect concentration are produced. In this study, high quality graphene nanoplatelets consisting of 1-5 layers were produced at low voltage (3-4 V) using KOH solution as electrolyte. The effect of electrolyte stirring on the characteristics of graphene was studied. The stirring of electrolyte during electrolysis showed profound effect on the characteristics of graphene. The scanning electron microscopic (SEM) analysis showed that the stirring of electrolyte increased the average size of graphene nanoplatelets to 360 nm from 253 nm (without stirring). Raman spectroscopy indicated the presence of 1-5 layers of carbon atoms and the same was confirmed by transmission electron microscopy (TEM). A decrease in the defect concentration was noted with the increase in number of layers of carbon atoms in graphene produced with stirring.