Reduction and nitridation of graphene oxide (GO) films at room temperature using inductively coupled NH3 plasma

• Plasma-assisted nitridation and reduction on GO films were performed at room temperature.
• Oxygen groups in the near-surface of GO films rapidly removed in less than 10 min.
• The [O/C] and [N/C] ratio were changed from 45% and 1.8% to 24% and 9.3%, respectively.
• The conductivity of GO films increased from 100 to 1666 S/m with plasma treatment time.
• Plasma-assisted process is an effective method at room temperature for very thin GO films.

Graphene oxide (GO) films were treated at room temperature by inductively coupled NH3 plasma. Oxygen functional groups on the surface of GO films were rapidly removed in less than 10 min, and nitrogen components were incorporated into the vacancies of oxygen groups. The ratio of [N/C] was reached to 9% and [O/C] was reduced from 45% to 25% within 10 min. Otherwise, the electrical conductivity of reduced GO (r-GO) films was gradually increased from 100 to 1666 S/m with plasma treatment time. From these results, it was conjectured that the defects on sp2 domains of GO films were consistently recovered after the saturation of [N/C] and [O/C] ratios. The process developed in this study is suitable for a very simple, scalable, eco-friendly and rapid surface-modification technique operating at room temperature.