Simultaneous Reduction and Surface Functionalization of Graphene Oxide by Natural Cellulose with the Assistance of the Ionic Liquid

An environmentally friendly method for preparation of multifunctional free-standing papers composed of reduced graphene oxide (RGO) and cellulose has been developed. The results show that the cellulose can effectively reduce the graphene oxide (GO) nanosheets in ionic liquids and the cellulose can be adsorbed onto the basal planes of the resulted RGO at the same time. Since cellulose is a natural, inexpensive, renewable, nontoxic, and biodegradable polymer, this approach presents a facile and cost-effective method to synthesize highly water-dispersible and stable functionalized graphene nanosheets (termed as RGO-CL) on a large scale. Furthermore, highly ordered RGO-CL composite papers are fabricated by flow-directed assembly of individual hybrid RGO-CL nanosheets and show a robust mechanical flexibility and significantly improved biocompatibility and conductivity, and have therefore potential applications in biomedical scaffolds for tissue engineering, medical devices, and so on.