Controlled synthesis of large-area and patterned electrochemically reduced graphene oxide films

A study was conducted to demonstrate the first simple, efficient, low-cost, and environmentally friendly electrochemical method to produce electrochemically reduced graphene oxide (ER-GNO) film with an O/C ratio of less than 6.25%. The controllable synthesis of large-area and patterned ER-GNO films with thickness ranging from a single monolayer to several microns was achieved on various conductive and insulating substrates by coupling the method with a spray-coating technique. GNO slurry was obtained by the modified Hummers method that was used to fabricate GNO films on substrate surfaces by spray coating. Each spraying cycle consisted of a 1-s-long spray of a solution GNO and 20 s drying under an infrared lamp. GNO platelets froze upon contact with the substrate as the solvent underwent fast evaporation that combined small droplet size with rapid evaporation to avoid the concentration process that occurred upon slow solvent loss.