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Lookup NU author(s): Dr Rambabu Gutru, Professor Mohamed MamloukORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2022, The Author(s). This study examines the effect of pretreatment and doping to enhance the ORR activity of multiwalled carbon nanotubes (MWCNTs). Melamine and thio-urea are chosen as precursors for mono and co-doping, respectively. A series of samples with pristine and pretreated CNTs are prepared and characterized physicochemically by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) and electrochemically by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The obtained results show that co-doping is an effective way for improving ORR activity, due to the synergistic effect of N and S for changing the charge and spin density, respectively. Moreover, thio-urea favors the proportion of pyridinic and graphitic nitrogen configurations within doped samples. As a consequence, our synthesis method gives samples with superior ORR activity. The maximum ORR activity is obtained for NS-OX-CNTs which shows an over potential of 0.95 V vs RHE at 0.1 mA/cm2, which is comparable to Pt/C (0.98 V vs RHE). The electron transfer number (n) is calculated as 3.9 at 0.4 V which suggests that the ORR proceeds through a dominant 4 e− path. These comparable half-cell results to that of Pt/C pave the way for further testing as cathode materials for anion exchange membrane fuel cells (AEMFC). Graphical abstract: [Figure not available: see fulltext.]
Author(s): Rambabu G, Turtayeva Z, Xu F, Maranzana G, Emo M, Hupont S, Mamlouk M, Desforges A, Vigolo B
Publication type: Article
Publication status: Published
Journal: Journal of Materials Science
Year: 2022
Volume: 57
Pages: 16739-16754
Online publication date: 04/09/2022
Acceptance date: 16/08/2022
Date deposited: 23/09/2022
ISSN (print): 0022-2461
ISSN (electronic): 1573-4803
Publisher: Springer Nature
URL: https://doi.org/10.1007/s10853-022-07653-3
DOI: 10.1007/s10853-022-07653-3
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