Nitrogen-doped carbon monolith for alkaline supercapacitors and understanding nitrogen-induced redox transitions

Wang, Da-Wei and Li, Feng and Yin, Li-Chang and Lu, Xu and Chen, Zhi-Gang and Gentle, Ian R. and Lu, Gao Qing (Max) and Cheng, Hui-Ming (2012) Nitrogen-doped carbon monolith for alkaline supercapacitors and understanding nitrogen-induced redox transitions. Chemistry: a European Journal, 18 (17). pp. 5345-5351. ISSN 0947-6539

Abstract

A nitrogen-doped porous carbon monolith was synthesized as a pseudo-capacitive electrode for use in alkaline supercapacitors. Ammonia-assisted carbonization was used to dope the surface with nitrogen heteroatoms in a way that replaced carbon atoms but kept the oxygen content constant. Ammonia treatment expanded the micropore size-distributions and increased the specific surface area from 383 m 2 g -1 to 679 m 2 g -1. The nitrogen-containing porous carbon material showed a higher capacitance (246 F g -1) in comparison with the nitrogen-free one (186 F g -1). Ex situ electrochemical spectroscopy was used to investigate the evolution of the nitrogen-containing functional groups on the surface of the N-doped carbon electrodes in a three-electrode cell. In addition, first-principles calculations were explored regarding the electronic structures of different nitrogen groups to determine their relative redox potentials. We proposed possible redox reaction pathways based on the calculated redox affinity of different groups and surface analysis, which involved the reversible attachment/detachment of hydroxy groups between pyridone and pyridine. The oxidation of nitrogen atoms in pyridine was also suggested as a possible reaction pathway.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published version cannot be displayed due to copyright restrictions.
Faculty / Department / School: No Faculty
Date Deposited: 16 Jun 2017 04:45
Last Modified: 16 Jun 2017 04:45
Uncontrolled Keywords: carbon; doping; microporous materials; redox chemistry; supercapacitors; ammonia treatment; carbon atoms; carbon electrode; carbon monoliths; ex situ; first-principles calculation; heteroatoms; hydroxy groups; micropores; N-doped; nitrogen atom; nitrogen group; nitrogen-doped; oxygen content; porous carbon materials; porous carbons; pyridones; reaction pathways; redox chemistry; redox potentials; redox transition; super capacitor; three electrode cells; applied mathematics; chemical products generally; chemical reactions; applied physics generally; chemical plants and equipment; computer software, data handling and applications; computer circuits and logic elements; chemistry
Fields of Research : 03 Chemical Sciences > 0303 Macromolecular and Materials Chemistry > 030302 Nanochemistry and Supramolecular Chemistry
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970103 Expanding Knowledge in the Chemical Sciences
Identification Number or DOI: 10.1002/chem.201102806
URI: http://eprints.usq.edu.au/id/eprint/31722

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