Effect of feed rate on the production of nitrogen-doped graphene from liquid acetonitrile

We have investigated the production of nitrogen-doped graphene (NG) from liquid acetonitrile and demonstrated that there is a critical feed rate of acetonitrile for the growth of NG. Graphene sheets could be obtained at feed rate lower than 0.08 mL/min. While at 0.08 mL/min or above, only polycrystalline carbon films could be obtained. Therefore, selective synthesis of NG or carbon films could be achieved by simply altering the feed rate of acetonitrile, which provides an effective way to control the growth of NG sheets. Furthermore, NG sheets (0.06 mL/min sample) and carbon films (0.08 mL/min sample) exhibit light transmittance of ∼90% and 70% at 550 nm, and sheet resistance of ∼1400 and 1000 Ω/sq, respectively, showing their potential applications in carbon-based nanoelectronics.