Effect of oxygen and hydrogen addition on the low-temperature synthesis of carbon nanofibers using a low-temperature CO/Ar DC plasma

Abstract The low-temperature synthesis of carbon nanofibers was demonstrated. When a small amount of O 2 was added to the CO/Ar plasma, the diameter of the CNFs decreased and the deposition of amorphous carbon and fiber bundling were suppressed. On the other hand, when H 2 was added, the diameter increased, and at higher H 2 flow rates, only smooth carbon film was deposited. At the optimum oxygen concentration of CO/O 2 = 1/0.003, vertically aligned free-standing CNFs can be synthesized at low temperature as low as 90 °C. Our spectroscopic study reveals that there is a steady correlation between C 2 radical formation and CNFs growth.