Hierarchical cobalt-nitride and-oxide co-doped porous carbon nanostructures for highly efficient and durable bifunctional oxygen reaction electrocatalysts
- Hierarchical cobalt-nitride and-oxide co-doped porous carbon nanostructures for highly efficient and durable bifunctional oxygen reaction electrocatalysts
- 남석우; 채근화; 김진영; 박현서; 조영석; 변아영; 이경진; 임아연; 신동윤; Alina Begley; 임동희; 성영은; 이관영
- Issue Date
- VOL 9, NO 41-15855
- Here we report the preparation of hollow microspheres with a thin shell composed of mixed cobalt nitride (Co– N) and cobalt oxide (Co– O) nanofragments encapsulated in thin layers of nitrogen-doped carbon (N– C) nanostructure (Co– N/Co– O@N– C) arrays with enhanced bifunctional oxygen electrochemical performance. The hybrid structures are synthesized via heat treatment of N-doped hollow carbon microspheres with cobalt nitrate, and both the specific ratio of these precursors and the selected annealing temperature are found to be the key factors for the formation of the unique hybrid structure. The as-obtained product (Co– C) presents a large specific surface area (493 m2 g− 1), highlevel heteroatom doping (Co– N, Co– O, and N– C), and hierarchical porous nanoarchitecture containing macroporous frameworks and mesoporous walls. Electronic interaction between the thin N– C layers and the encapsulated Co– N and Co– O nanofragments efficiently optimizes oxygen adsorption properties on the Co– C and thereby triggers bifunctional oxygen electrochemical activity at the surface. The Co– C nanohybrid exhibited a high onset potential of 0.93 V, and a limiting current density of 5.6 mA cm− 2 indicating 4-electron oxygen reduction reaction (ORR), afforded high catalytic
activity for the oxygen evolution reaction (OER) and even exceeded the catalytic stability of the commercial precious electrocatalysts; furthermore, when integrated into the oxygen electrode of a regenerative fuel cell device, it exhibited high-performance oxygen electrodes for both the ORR and the OER.
- Appears in Collections:
- KIST Publication > Article
- Files in This Item:
There are no files associated with this item.
- RIS (EndNote)
- XLS (Excel)
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.