Facile and highly efficient preparation of semi-transparent, patterned and large-sized reduced graphene oxide films by electrochemical reduction on indium tin oxide glass surface

Graphene and/or reduced graphene oxide (RGO) films have widespread applications in many fields, due to their extraordinary physical and chemical properties. Several physical and chemical methods for preparing graphene and RGO films have been reported, but a facile and efficient method is still lacking. Here, we report a facile and effective electrochemical method to prepare RGO films from a GO aqueous solution. By applying a low direct current voltage (several volts) to an electrolytic cell made with two indium tin oxide (ITO) glass plates for a short time (in seconds), GO nanosheets close to the cathodal ITO glass surface are reduced and directly deposited on the surface to form RGO films, which show metallic luster and semi-transparency. The thickness and transmittance of the RGO films can be adjusted by changing reduction time and applied voltage. Moreover, patterned RGO films could be obtained by using patterned ITO glass plates. Very impressively, large-sized RGO films can be prepared on a large-sized ITO glass plate, and they can be peeled off by using an adhesive tape. The facile preparation of RGO films with controllable thickness, transmittance, pattern and size would facilitate their practical applications.