Journal
ELECTROCHIMICA ACTA
Volume 313, Issue -, Pages 1-9Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.electacta.2019.05.015
Keywords
Top-down synthesis; S-doped graphene; Electrochemical exfoliation; Oxygen reduction reaction; Oxygen evolution reaction
Categories
Funding
- Daegu University Research Grant, 2018
Ask authors/readers for more resources
In this study, top-down synthesis of sulfur-doped graphene nanosheets (SDGNs) by simple electrochemical exfoliation was explored as a means of producing metal-free electrocatalysts for oxygen reduction and oxygen evolution reactions (ORR and OER, respectively). In a typical procedure, graphite foils were used to obtain bulk quantities of SDGN catalysts in the presence of thiosulfate as a sulfur source. Highly stable colloidal dispersions of SDGNs were obtained by applying a voltage of 15 V at an optimized Na2S2O3:H2SO4 molar ratio of 5 : 1 (denoted SDGN(5)). Physicochemical characterizations by Raman spectroscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy confirmed the existence of sulfur and its electronic/structural properties in graphene nanosheets. In alkaline media, SDGN(5)-modified electrodes were comparable or superior to pristine graphene and a benchmark commercial platinum-based electrodes in terms of stability, methanol tolerance, n values, and onset potential for ORR and OER. The specific capacitance (149.9 F g(-1)) of SDGN(5) supported its excellent ORR/OER performance and enhanced surface area. (C) 2019 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available