Semiconducting Carbon Nanofibers and Hydrogen Storage

Semiconducting carbon nanofibers (CNF) were prepared from three different sources, i.e., acetylene, ethanol, and cotton by the chemical vapor deposition (CVD) process at 850°C. CNF was then activated with KOH to attain high surface area. The characteristic study of the CNF was done to get information about the structure by SEM, TEM, and XRD. Activated CNF showed presence of more pores than non‐activated ones (in CNF from all 3 precursors), thus increasing the reactive surface area. Resistivity of activated CNFs was measured by the two‐probe method. An increase in hydrogen adsorption isotherm was recorded in activated CNF. The maximum hydrogen adsorption was noted in CNF obtained from cotton that showed the semiconducting nature; it was around 0.65 wt.% at 11 Kg/cm² and 3 wt.% at 135 Kg/cm². Whereas acetylene and alcohol‐derived CNF showed only 0.51 wt.% and 0.42 wt.% hydrogen adsorption respectively; maybe it was because they had less available surface area. Moreover, the negative TCR was lowest in cotton derived CNF (0.23 eV); confirming it to be a semiconducting material.

Keywords:

• semiconducting
• carbon nanofiber
• activation
• hydrogen storage
• acetylene
• alcohol
• cotton

We are grateful for financial support from the BRNS for this project. We are also thankful to our Principal Dr. Naresh Chandra and all the Nano Technology Laboratory researchers, for support of and motivation for the experiments.