The combination of metal-organic frameworks and polydopamine nanotubes aiming for efficient one-dimensional oxygen reduction electrocatalyst

Abstract

Metal organic frameworks (MOFs) derived carbon nanomaterial is among the most promising electrocatalysts as it has high surface area and plentiful doping elements. A further improvement in their performance is focusing on its diffusion-limited microporous nanostructure and the relatively poor graphitic degree. Herein, a novel 1D Co/N co-doped carbon nanomaterial (Co/N-CNT) with hierarchical micro- and mesoporous structure is prepared via epitaxial growth of ZIF-67 nanocrystals on polydopamine nanotubes (PDA NTs), followed by pyrolysis and acid leaching. Thanks to the inherent nature of PDA NTs, ZIF-67 nanocrystals were restrictedly grown on their surface homogeneously. After further treatment, the ZIF-67 derived Co/N doped carbon layers not only protect the integrity of 1D structure, but also exhibit “niches” like mesoporous structure to expose more active sites toward boosting oxygen reduction reaction. The rational designed Co/N-CNT composites have a comparable ORR activity to the commercial Pt/C catalyst, superior methanol tolerance and long-time durability in alkaline media, which may shed light on their further application toward energy conversion and storage.