Direct imaging of copper catalyst migration inside helical carbon nanofibers
By using a double-aberration-corrected (scanning) transmission electron microscope (STEM/TEM) at an acceleration voltage of only 80 kV, we demonstrate that, due to the low solubility of copper (Cu) in carbon and its affinity with oxygen (O), single-crystal Cu catalysts dissociate into small cuprous oxide (Cu2O) nanoparticles after the growth of carbon nanofibers, and Cu2O nanoparticles ultimately localize on the fiber surfaces. This new finding is a step toward a better understanding of the interactions between Cu catalysts and carbon nanomaterials and could suggest a simple and effective method for eliminating Cu impurities from the fibers.
Physics, Astronomy, and Materials Science
Dong, Lifeng, Liyan Yu, Zuolin Cui, Hongzhou Dong, Peter Ercius, Chengyu Song, and Thomas Duden. "Direct imaging of copper catalyst migration inside helical carbon nanofibers." Nanotechnology 23, no. 3 (2011): 035702.