The electrocatalytic characterization and mechanism of carbon nanotubes with different numbers of walls for the VO2+/VO2+ redox couple. Issue 11 (5th March 2018)

• Record Type: Journal Article
• Authors: Lv, Zhaoqian; Zhang, Jin; Lv, Yang; Cheng, Yi; Jiang, San Ping; Xiang, Yan; Lu, Shanfu
• Is Part Of: Physical chemistry chemical physics. Volume 20:Issue 11(2018)
• Page Start: 7791
• Page End: 7797
• Publication Date: 2018-03-05
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c7cp08683k
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Remarkable differences in the electrocatalytic activity and reversibility were observed among CNTs with wall numbers for the VO2 + /VO 2+ redox. Abstract : Carbon nanotubes (CNTs) have been applied as catalysts in the VO2 + /VO 2+ redox, whereas the mechanism of CNTs for the redox reaction is still unclear. In this work, the mechanism of the VO2 + /VO 2+ redox is investigated by comparing the electrocatalytic performance of CNTs with different distributions. For different CNTs, the peak current density of the VO2 + /VO 2+ redox increases with increasing content of oxygen-functional groups on the surface of CNTs, especially the carboxyl group which is proved as active sites for the redox reaction. Moreover, the reversibility of the VO2 + /VO 2+ redox decreases with increasing defects of CNTs, as the defects affect the charge transfer of the catalytic reaction. Nevertheless, when a multi-walled CNT sample is oxidized to achieve a high content of oxygen functional groups and defects, the peak current density of the redox reaction increases from 38.5 mA mg −1 to 45.4 mA mg −1 whilst the peak potential separation (Δ E p ) also increases from 0.176 V to 0.209 V. Overall, a balance between the oxygen functional groups and the defects of CNTs affects the peak current and the reversibility for the VO2 + /VO 2+ redox.