It is essential but still challenging to design and construct inexpensive, highly active bifunctional oxygen electrocatalysts for the development of high power density zinc–air batteries (ZABs). Herein, a CoFe‐S@3D‐S‐NCNT electrocatalyst with a 3D hierarchical structure of carbon nanotubes growing on leaf‐like carbon microplates is designed and prepared through chemical vapour deposition pyrolysis of CoFe‐MOF and subsequent hydrothermal sulfurization. Its 3D hierarchical structure shows excellent hydrophobicity, which facilitates the diffusion of oxygen and thus accelerates the oxygen reduction reaction (ORR) kinetic process. Alloying and sulfurization strategies obviously enrich the catalytic species in the catalyst, including cobalt or cobalt ferroalloy sulfides, their heterojunction, core–shell structure, and S, N‐doped carbon, which simultaneously improve the ORR/OER catalytic activity with a small potential gap (Δ
MoO2@C core shell nanofibers are synthesized via a simple electrospinning method with a single nozzle. The formation mechanism of MoO2@C core shell nanofibers is investigated in detail and it is discovered that the phase‐segregation phenomenon may be the main driving force of thermodynamics to form MoO2@C core shell nanofibers, and the high temperature as the dynamic factor can accelerate the formation of these core shell nanofibers. The carbon shell of the MoO2@C core shell nanofibers acts as both conductive bond to increase electrical conductivity and structural skeleton to maintain the integrity of MoO2during Li+insertion/extraction to achieve both high specific capacity and good cyclic stability. So as an anode for lithium‐ion batteries, the MoO2@C core shell nanofiber electrode exhibits high specific capacity and extraordinary lifetime even at a large current density. Their reversible capacities are 665 mA h g−1in the 600th cycle at 0.5 A g−1. Even at a high current density of 1 A g−1, a capacity of 537 mA h g−1is obtained after 600 cycles. The present work may provide a facile and broadly applicable way for the fabrication and utilization of metal oxide/carbon core shell composites in fields of batteries, catalysts, and fuel cells.
more » « less- NSF-PAR ID:
- 10234156
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials Interfaces
- Volume:
- 4
- Issue:
- 3
- ISSN:
- 2196-7350
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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