J. Mater. Sci. Technol. ›› 2016, Vol. 32 ›› Issue (6): 533-538.DOI: 10.1016/j.jmst.2016.01.001

• Orginal Article • Previous Articles     Next Articles

Ozone-Mediated Functionalization of Multi-Walled Carbon Nanotubes and Their Activities for Oxygen Reduction Reaction

Hengheng Xia1, 2, Yexin Zhang2, Chunlin Chen2, Wenlin Wu2, Ken Yao1, *, Jian Zhang2, **   

  1. 1 Department of Chemistry, Shanghai University, Shanghai 200444, China; 2 Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo 315201, China
  • Received:2015-04-01 Online:2016-06-10
  • Contact: Corresponding author. Prof., Ph.D.; Tel.: +86 21 56388125; Fax: +86 21 56388125. (K. Yao). E-mail address: yao850618jp@yahoo.co.jp (K. Yao). Prof., Ph.D.; Tel.: +86 574 87615956; Fax: +86 574 86669487. (J. Zhang). E-mail address: jzhang@nimte.ac.cn (J. Zhang).
  • Supported by:
    This work was financially supported by the National Natural Science Foundation of China (Nos. 21307142 and 21403261) and Ningbo Science and Technology Bureau (No. 2014D10004).

Abstract: The functionalization of multi-walled carbon nanotubes (MWCNTs) by ozone treatment has been systematically investigated by using Raman spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), organic elemental analysis (OEA) and Boehm titration. The results showed that the functionalization process occurred at defective sites (opened mouths, tube caps, debris, etc.) before opening caps and truncating walls, and finally the graphitic structure was deteriorated. The surface oxygen content first increased with the treatment time but kept at around 8.0 wt% after 5?h. The analysis of the distribution of oxygen-containing groups revealed that phenolic hydroxyl was gradually converted to carboxyl and lactone. The carboxyl was found to play a pivotal role to reduce the over-potentials when we used the functionalized MWCNTs as the catalyst for oxygen reduction reaction (ORR).

Key words: Multi-walled carbon nanotubes, Ozone oxidation, Functionalization, Oxygen reduction reaction