Structural and electronic characteristics induced by carbonization control of mesoporous carbon nanofibers

• Controlled structural property and electrical property of mesoporous carbon nanofiber depending on change of carbonization temperature.
• Increasing La, Lc and decreasing d-space at higher carbonization temperature.
• The lower Ea and energy gap are reduced by high carbonization temperature.
• Developing mesoporous carbon nanofiber with higher conductivity is expected to be useful in application for gas sensor.

Mesoporous carbon nanofibers (MCNFs) are fabricated at various carbonization temperatures. The carbonization temperature plays a key role in determining the structural characteristics and the electronic properties of MCNFs. The band gap energies of MCNFs are estimated to be 0.080, 0.036, and 0.014 eV at the carbonization temperatures of 600, 900, and 1200 °C, respectively. The MCNF carbonized at 1200 °C has the highest stacking height of graphene planes (Lc) and the largest number of graphene layers (Lc/d). Raman data show the intensity ratio of D to G peaks, which is related to the graphene size (La). La increases with increasing the carbonization temperature. In addition, as the carbonization temperature increases, the conductivity of MCNF increases due to larges values of Lc, La, and Lc/d.