Polyacrylonitrile/pitch nanofibers were prepared by electrospinning as a precursor for a gas sensor material. Pitch nanofibers were properly fabricated by incorporating polyacrylonitrile as an electrospinning supplement component. Polyacrylonitrile/pitch nanofibers were activated with steam at various temperatures followed by subsequent carbonization to make carbon nanofibers with a highly conductive graphitic structure. Steam activation was effective in facilitating gas adsorption onto the carbon nanofibers due to the increased surface area. The carbon nanofibers activated at 800°C had a larger surface area and a lower micro pore fraction resulting in a higher variation in electrical resistance for improved CO gas sensing properties.

Abstract
 1. Introduction
 2. Experimental
  2.1. PAN/pitch nanofiber preparation
  2.2. Thermal treatment and steam activation
  2.3. Characterizations of the carbon nanofibers
 3. Results and Discussion
  3.1. Surface characterization of the PAN/pitchnanofibers
  3.2. Effect of the pitch content on the electricalproperties of the carbon nanofibers
  3.3. Pore structure of the carbon nanofibers
  3.4. CO gas sensing characteristics of the carbonnanofibers
 4. Conclusions
 Conflict of Interest
 Acknowledgements
 References

• Jeongsik Kim(Department of Industrial Chemistry, Chungnam National University)
• Hyung-Il Kim(Department of Industrial Chemistry, Chungnam National University) Corresponding Author
• Jumi Yun(Hanwha Chemical Research and Development Center)