1. Vaporized-salt-induced sp3-hybridized defects on nitrogen-doped carbon surface towards oxygen reduction reaction.
- Author
-
Cao, Yuanjie, Liu, Zhang, Tang, Yuanting, Huang, Chaojun, Wang, Zhili, Liu, Feng, Wen, Yanwei, Shan, Bin, and Chen, Rong
- Subjects
- *
OXYGEN reduction , *REACTIVE oxygen species , *CARBON , *SURFACE structure , *HIGH temperatures , *SALTS - Abstract
The intrinsic carbon defects including pentagons, vacancies and sp3-hybridized carbon have recently been proposed as efficient reactive sites for oxygen reduction reaction (ORR). Nevertheless, it is still a great challenge to controllably introduce the intrinsic defects into carbon materials. Herein, a universal defect-engineering method via vaporized salt is reported to modify the N-doped carbon surface with abundant sp3-hybridized carbon defects. At an elevated temperature, the vaporized sodium chloride is found to selectively modulate the surface structure of carbon material. The obtained carbon-based electrocatalyst delivers an outstanding electrocatalytic ORR property with a half-wave potential (E 1/2) of 0.85 V vs. RHE and an excellent performance in zinc air battery (ZAB) test. The analysis of components and structures of surface elements via XANES and XPS reveals that the increasing sp3-hybridized carbon defects, induced by the vaporized-salt modification, are responsible for the enhancement of ORR performance. The theoretical calculations further suggest the sp3 component hybridizes with original sp2 carbon, forming efficient sp2/sp3 hybridized carbon sites towards ORR. Additionally, other halide salts are proved to have the similar effect on promoting ORR activity and this method can expand to other carbon-based materials, suggesting its universality and significance in synthesis of defect-rich carbon-based materials. [Display omitted] • A universal defect-engineering method via vaporized salt halide was developed. • The vaporized-salt-treated catalysts exhibited a superior ORR activity. • XANES, XPS, Raman and DFT calculations were applied to reveal the active sites. • The raised ORR activity was induced by the increasing sp3 carbon defects. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF