title: Direct imaging of copper catalyst migration inside helical carbon nanofibers.
abstract: 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.
authors.affiliation: College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China. DongLifeng@yahoo.com
authors.forename: Lifeng
authors.initials: L
authors.lastname: Dong
authors.forename: Liyan
authors.initials: L
authors.lastname: Yu
authors.forename: Zuolin
authors.initials: Z
authors.lastname: Cui
authors.forename: Hongzhou
authors.initials: H
authors.lastname: Dong
authors.forename: Peter
authors.initials: P
authors.lastname: Ercius
authors.forename: Chengyu
authors.initials: C
authors.lastname: Song
authors.forename: Thomas
authors.initials: T
authors.lastname: Duden