Abstract
For expanding the functionalities of carbon (C) nanofibers, it remains a challenge to optimize the hybrid structures of metal/C nanofibers such as the secondary nanostructures of C nanofibers and the morphologies of metallic species. Herein, for the first time, we successfully fabricated diversely structured metal/C nanofibers from the same electrospun nanofiber by modulating redox reactions during the calcination. It is based on the selective oxidation, which induces metal reduction and C oxidation. Oxygen partial pressure enables to control the degree of C decomposition. This method is applicable for metals whose oxidation tendency is lower than C. In the pressure range from 1.0 to 6.0×10-2 Torr, fully filled C nanofibers, Cu/C core/shell nanofibers, hollow C nanofibers, and porous/hollow C nanofibers are formed accordingly. Pressure and time as kinetic factors of calcination affect the nanoscale Kirkendall effect used for hollow C structure formation. As more C decomposes, the inner diameter of the hollow C structure increases. After formation of the hollow C structure, Cu diffuses either inward or outward for stress relaxation and then agglomerates by Ostwald ripening. Our one-step synthesis provides a standard fabrication scheme for optimizing the structures of metal/C nanofibers, which can induce high performances in widespread applications.
| Original language | English |
|---|---|
| Pages (from-to) | 273-281 |
| Number of pages | 9 |
| Journal | Carbon |
| Volume | 82 |
| Issue number | C |
| DOIs | |
| State | Published - 2015 |
Bibliographical note
Funding Information:This work was supported by the Global Leading Technology Program of the Office of Strategic R&D Planning (OSP) funded by the Korean government (Ministry of Trade, Industry and Energy) (No. 10042537 ). This work was also supported by LS-Nikko Copper Inc. XRD and TEM analysis were supported by the Research Institute of Advanced Materials (RIAM) in Seoul National University.