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.