We investigate the application of the onion-like carbon (OLC) as an electrocatalyst for [VO]2+/[VO2]+ redox flow reaction; its performance (electrocatalytic activity and reversibility) strongly increases with the synthesis to peak at 1800 °C in 1000–2000 °C range. The dopant/modification-free, optimized redox performances of the OLC is comparable to some of the best data in the literature of various types of carbon materials with post-synthesis modifications or doping. Mechanism behind such performance optimization is investigated employing various physical/electrochemical analyses as well as the first-principles calculations. We demonstrate that the carbon dangling bonds or the crystalline defects, generated by an inherent mechanism unique to the OLC, played a pivotal role in determining the electrocatalytic performances.
Bibliographical noteFunding Information:
This work was supported by the institutional program grant (Grant No. 2E27120 ) from Korea Institute of Science and Technology (KIST). This study was also partly supported by another KIST institutional program (Grant No. 2E26940 ). This study was also partly supported by the computational resources of the HPCI system (Project ID: hp160051 , hp170190 ). The authors are grateful to M.K. Cho (in Advanced Analysis Center, KIST) for the comments for HR-TEM characterization, to Dr. K.-W. Chae at HoSeo University for his helps in the vacuum annealing process.
© 2017 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Materials Science(all)