A new strategy to access Co/N co-doped carbon nanotubes as oxygen reduction reaction catalysts

Carbon nanotubes (CNTs), as one-dimensional nanomaterials, show great potential in energy conversion and storage due to their efficient electrical conductivity and mass transfer. However, the security risks, time-consuming and high cost of the preparation process hinder its further application. Here, we develop that a negative pressure rather than a following gas environment can promote the generation of cobalt and nitrogen co-doped CNTs (Co/N-CNTs) by using cobalt zeolitic imidazolate framework (ZIF-67) as a precursor, in which the negative pressure plays a key role in adjusting the size of cobalt nanoparticles and stimulating the rearragement of carbon atoms for forming CNTs. Importantly, the obtained Co/N-CNTs, with high content of pyridinic nitrogen and abundant graphitized structure, exhibit superior catalytic activity for oxygen reduction reaction (ORR) with half-wave potential (E-1/2) of 0.85 V and durability in terms of the minimum current loss (2%) after the 30,000 s test. Our development provides a new pathway for large-scale and cost-effective preparation of metal-doped CNTs for various applications. (C) 2020 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

This study demonstrates that Co/N-CNTs synthesized under negative pressure exhibit superior catalytic activity for oxygen reduction reaction. The materials show efficient electrical conductivity and mass transfer potential.