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A complex study of the dependence of the reduced graphite oxide electrochemical behavior on the annealing temperature and the type of electrolyte. / Iurchenkova, Anna A.; Lobiak, Egor V.; Kobets, Anna A. et al.
In: Electrochimica Acta, Vol. 370, 137832, 20.02.2021.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - A complex study of the dependence of the reduced graphite oxide electrochemical behavior on the annealing temperature and the type of electrolyte
AU - Iurchenkova, Anna A.
AU - Lobiak, Egor V.
AU - Kobets, Anna A.
AU - Kolodin, Alexey N.
AU - Stott, Ash
AU - Silva, S. Ravi P.
AU - Fedorovskaya, Ekaterina O.
N1 - Publisher Copyright: © 2021 Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/2/20
Y1 - 2021/2/20
N2 - In this work we investigate the influence of thermal treatment of reduced graphite oxide (RGO) on its functional composition and electrochemical performance. It is found that carboxyl, carbonyl, hydroxyl and epoxy groups are present on the RGO surface, witch when subject to thermal annealing in the temperature range 230–250°C can be controllably modified. In the process of thermal annealing, we show the formation of quinoid groups due to an increase in the number of defects. Decrease of the number of layers in RGO material and the quantity of oxygen-containing functional groups (OCFG) also occurs. With increase in annealing temperature, sequential removal of OCFG occurs as follows: carboxyl (250°C–600°C), hydroxyl (600°C–800°C), carbonyl and quinoid (700°C–1000°C). Electrochemical measurements over a wide range of pH values of the buffer electrolytes is possible to correlate the peaks in the cyclic voltammogram curves with the redox reactions of oxygen-containing functional groups as a function of applied potential. Peaks correlated with specific redox reactions which are identified as two-electron. The dependence of the specific capacities of materials on the electrolyte type has been studied. Highest capacitance was detected in 1M NaOH at a scan rate 2 mVs−1 and is equal to 210 Fg−1.
AB - In this work we investigate the influence of thermal treatment of reduced graphite oxide (RGO) on its functional composition and electrochemical performance. It is found that carboxyl, carbonyl, hydroxyl and epoxy groups are present on the RGO surface, witch when subject to thermal annealing in the temperature range 230–250°C can be controllably modified. In the process of thermal annealing, we show the formation of quinoid groups due to an increase in the number of defects. Decrease of the number of layers in RGO material and the quantity of oxygen-containing functional groups (OCFG) also occurs. With increase in annealing temperature, sequential removal of OCFG occurs as follows: carboxyl (250°C–600°C), hydroxyl (600°C–800°C), carbonyl and quinoid (700°C–1000°C). Electrochemical measurements over a wide range of pH values of the buffer electrolytes is possible to correlate the peaks in the cyclic voltammogram curves with the redox reactions of oxygen-containing functional groups as a function of applied potential. Peaks correlated with specific redox reactions which are identified as two-electron. The dependence of the specific capacities of materials on the electrolyte type has been studied. Highest capacitance was detected in 1M NaOH at a scan rate 2 mVs−1 and is equal to 210 Fg−1.
KW - Cyclic voltammetry
KW - Fourier transform infrared spectroscopy
KW - Graphite oxide
KW - Reduced graphite oxide
KW - Supercapacitor
KW - X-ray photoelectron spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85099691794&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2021.137832
DO - 10.1016/j.electacta.2021.137832
M3 - Article
AN - SCOPUS:85099691794
VL - 370
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
M1 - 137832
ER -
ID: 27590400