The synthesis of carbon nanotubes (CNTs) is usually done by metallic catalysts with a gaseous carbon precursor at high temperature. Yet, mild synthesis conditions can broaden the application of CNTs and their composites. In the present work, it is unraveled why partially substituted Fe ions in 2D MnO2 nanosheets lead to the growth of CNTs at low temperatures of 400−500 °C. The local formation of Fe3C by carbon precursor explains the unusually high catalytic activity of 2D FexMn1−xO2 nanosheets for preparing CNTs. Finally, Fe3C is oxidized to Fe3C/FeOx yolk/shell morphology in ambient atmosphere after the CNT formation reaction. These results shed light on the development of novel catalyst materials that allow for efficiently prepare CNTs under mild conditions for their wider use in energy-harvesting applications.
Bibliographical noteFunding Information:
J.L. acknowledges financial support from the Alexander von Humboldt Foundation. This work was supported by a National Research Foundation of Korea (NRF) Grant funded by the government of Korea (MSIP) (no. NRF‐2020R1A2C3008671) and by the government of Korea (MSIT) (no. NRF‐2017R1A5A1015365).
© 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics