Catalytic twist-spun yarns of nitrogen-doped carbon nanotubes

Xavier Lepró, Raquel Ovalle-Robles, Márcio D. Lima, Ana Laura Elias Arriaga, Mauricio Terrones Maldonado, Ray H. Baughman

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

The treatment of free-standing sheets of multiwalled carbon nanotubes (MWNTs) with a NH 3/He plasma results in self-supporting sheets of aligned N-doped MWNTs (CN x). These CN x sheets can be easily twist spun in the solid state to provide strong CN x yarns that are knottable, weavable, and sewable. The CN x yarns exhibit tunable catalytic activity for electrochemically driven oxygen reduction reactions (ORR), as well as specific capacitances (up to 39 F·g -1) that are 2.6 times higher than for the parent MWNTs. Due to a high degree of nanotube alignment, the CN x yarns exhibit specific strengths (451 ± 61 MPa·cm 3·g -1) that are three times larger than observed for hybrid CN x/MWNT biscrolled yarns containing 70 wt.% CN x in the form of a powder. This difference in mechanical strength arises from substantial differences in yarn morphology, revealed by electron microscopy imaging of yarn cross- sections, as well as the absence of a significant strength contribution from CN x nanotubes in the biscrolled yarns. Finally, the chemical nature and abundance of the incorporated nitrogen within the CN x nanotubes is studied as function of plasma exposure and annealing processes using X-ray photoelectron spectroscopy and correlated with catalytic activity.

Original languageEnglish (US)
Pages (from-to)1069-1075
Number of pages7
JournalAdvanced Functional Materials
Volume22
Issue number5
DOIs
StatePublished - Mar 7 2012

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All Science Journal Classification (ASJC) codes

  • Biomaterials
  • Electrochemistry
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

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