Ionic liquid-assisted exfoliation of graphite oxide for simultaneous reduction and functionalization to graphenes with improved properties

Abstract

A novel one-step approach for the pH-triggered electrochemically interacted exfoliation of graphene sheets in graphite oxide and simultaneous reduction and functionalization with the aid of the ionic liquid is reported. The developed method shows significant advantages over the conventional functionalized/chemically reduced graphene. Particularly, for the first time, no additional stabilizer or modifier is needed to stabilize the resulting processible graphene dispersion. The prepared graphene oxide and its functionalized graphene are characterized by SEM, TEM, FTIR, UV-vis, XRD, Raman, XPS, and NMR. The results indicate that, with the aid of the IL during the reaction, the resulting functionalized graphene shows improved organophilicity, good wettability and improved interfacial interactions as well as significant resistance to thermal degradation. The methodology paves a new way for use of the IL as a processing aid and reaction medium to promote chemical functionalization of graphene through the electrochemically interacted exfoliation of graphene sheets and can be expected to provide a new approach with great promise for its organophilic wettability and enhanced interfacial adhesion as well as improved thermal stability. Furthermore, the controlled modifications of graphene nanoreinforcements can also be expected to alter the nature of the interactions between components.