Advertisement

Preparation of Nitrogen-Doped Porous Carbon Nanofibers and the Effect of Porosity, Electrical Conductivity, and Nitrogen Content on Their Oxygen Reduction Performance

Authors

  • Dae-Soo Yang,

    1. Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700 (Republic of Korea), Fax: (+82) 44-860-1331
    Search for more papers by this author
    • These authors contributed equally to this work.

  • Dr. Sudeshna Chaudhari,

    1. Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700 (Republic of Korea), Fax: (+82) 44-860-1331
    Search for more papers by this author
    • These authors contributed equally to this work.

  • Prof. Kizhakke Palleeri Rajesh,

    1. Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700 (Republic of Korea), Fax: (+82) 44-860-1331
    Search for more papers by this author
  • Prof. Jong-Sung Yu

    Corresponding author
    1. Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700 (Republic of Korea), Fax: (+82) 44-860-1331
    • Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700 (Republic of Korea), Fax: (+82) 44-860-1331===

    Search for more papers by this author

Abstract

Nitrogen-doped carbon nanostructures are considered as a possible alternative to platinum-based catalysts for fuel cells. The surface density of catalytic sites, electrical conductivity, and nitrogen content play important roles in designing electrode materials for fuel cells. Herein, N-doped carbon fibers are prepared by electrospinning the poly(acrylonitrile) (PAN) solution followed by carbonization. Some of the key issues of the oxygen reduction reaction (ORR) are addressed in terms of nitrogen content, porosity, and electrical conductivity in the N-containing carbon nanofibrous system. Nitrogen content and the amount of the graphitic phase are varied by changing the carbonization temperature. In addition, N-doped carbon fibers with high porosity are prepared by electrospinning the solution mixture of poly(ethylene oxide) (PEO)/PAN followed by carbonization, and the porosity is tuned by varying the ratio of PEO to PAN. The effect of porosity or the surface density of catalytic sites on the ORR is studied. A medium porous sample prepared from the PEO/PAN mixture in a 1:1 ratio by carbonization at 1000 °C is found to be favorable for improved ORR performance for such a system. The observations made herein are explained in terms of trade-offs between electrical conductivity, nitrogen content, and surface density of active sites.

Ancillary