Green Energy & Environment (Jan 2017)

Co/N–C nanotubes with increased coupling sites by space-confined pyrolysis for high electrocatalytic activity

  • Jun Yang,
  • Laiquan Li,
  • Hong Yu,
  • Hongbo Geng,
  • Chengchao Li,
  • Xiaochen Dong

Journal volume & issue
Vol. 2, no. 1
pp. 23 – 29

Abstract

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Searching low cost and non-precious metal catalysts for high-performance oxygen reduction reaction is highly desired. Herein, Co nanoparticles embedded in nitrogen-doped carbon (Co/N–C) nanotubes with internal void space are successfully synthesized by space-confined pyrolysis, which effectively improve the cobalt loading content and restrict the encapsulated particles down to nanometer. Different from the typical conformal carbon encapsulation, the resulting Co/N–C nanotubes possess more cobalt nanoparticles embedded in the nanotubes, which can provide more coupling sites and active sites in the oxygen reduction reaction (ORR). Moreover, the one-dimensional and porous structure provides a high surface area and a fast electron transfer pathway for the ORR. And the Co/N–C electrode presents excellent electrocatalytic ORR activity in terms of low onset potential (30 mV lower than that of Pt/C), small Tafel slop (45.5 mV dec−1) and good durability (88.5% retention after 10,000 s). Keywords: Co nanoparticles, Nitrogen-doped carbon nanotubes, Oxygen reduction reaction