When supporting electrolyte matters – Tuning capacitive response of graphene oxide via electrochemical reduction in alkali and alkaline earth metal chlorides

Karačić, Dalibor; Korać, Selma; Dobrota, Ana S.; Pašti, Igor A.; Skorodumova, Natalia V.; Gutić, Sanjin J.

doi:10.1016/j.electacta.2018.11.173

Cited by 9 publications

(4 citation statements)

References 36 publications

(39 reference statements)

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“…The highest observed capacitances (83.5 and 98.9 F g −1 for DC 2 and ED 1 , respectively) are within the specific capacitance range reported for chemically reduced GO when examined in organic and aqueous solutions (99 to 135 F g −1 ) 62 and electrochemically produced rGO when examined in alkali and alkaline earth metal chlorides (maximum capacitances between 65 and 130 F g −1 ). 63 The cycle life during 500 charge/discharge cycles of the DC 5 and ED 5 coatings on the GCP electrodes in 1.0 M KOH was examined at a current density of ±1.6 mA cm −2 and plots of the specific capacitance vs cycle number are shown in Fig. S3.…”

Section: Resultsmentioning

confidence: 99%

Charge Capacitance and Hydrogen Storage Capacity of Drop Cast and Electrodeposited Reduced Graphene Oxide Coatings

Avraham

Kadosh

Korin

et al. 2021

J. Electrochem. Soc.

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Drop cast (DC) and electrodeposited (ED) graphene-based coatings on glassy carbon (GC) electrodes were subjected to various electro-reduction degrees. The ED coatings were characterized by more accumulated graphene sheets imperfections as observed by cross section TEM analysis. These coatings, when reduced at −1.6 V vs Hg/HgO showed more efficient removal of phenolic groups than DC ones treated at the same potential (remaining contents of 2.1 and 18.1%, respectively). They also showed lower charge transfer resistance (5.2 and 28 Ω cm2, respectively), higher capacitance (73.2 and 42.6 F g−1, respectively), and higher hydrogen storage capacity (119 and 57 mAh g−1, respectively). Moreover, they showed higher stability towards H2 charge/discharge cycles (retained hydrogen capacities of 95 and 40% after 15 and 6 cycles for ED and DC coatings reduced at −1.5 V, respectively). The superior performance properties of coatings obtained by ED and subsequently electro-reduced make them promising electrode materials for energy storage.

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Section: Resultsmentioning

confidence: 99%

Charge Capacitance and Hydrogen Storage Capacity of Drop Cast and Electrodeposited Reduced Graphene Oxide Coatings

Avraham

Kadosh

Korin

et al. 2021

J. Electrochem. Soc.

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“…Hence, in order to benefit from both GO and graphene, a balance between their desirable properties is necessary [ 20 ]. Recently, a precise modification of oxygen functionalities on graphene and the graphene oxide basal plane was proposed, in order to finely tune its properties [ 9 , 11 , 29 , 30 , 31 , 32 ]. The main challenge is to carry out a precise reduction process (using different reducing agents or reduction conditions), with the possibility of controlling both the reduction degree (the OFGs’ content) and the selectivity of the key OFGs’ removal [ 11 , 33 ].…”

Section: Introductionmentioning

confidence: 99%

“…The reduction of GO layers can be achieved using thermal, chemical, photoreduction, microwave irradiation and electrochemical methods [ 6 , 9 , 32 , 38 ]. Electrochemical reduction, a room temperature process, is considered a green route, since neither toxic chemicals (which are harmful to both humans and the environment, and can contaminate the final product) nor high temperatures are employed during the electrochemical reduction process [ 10 , 16 , 21 , 29 , 39 ]. Moreover, the simple manipulation of the electrochemical reduction process of the graphene oxide can be achieved through controlling the potential, reduction time and electrolyte choice [ 10 , 33 , 40 , 41 ].…”

Section: Introductionmentioning

confidence: 99%

Effect of Electrolytic Medium on the Electrochemical Reduction of Graphene Oxide on Si(111) as Probed by XPS

et al. 2021

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The wafer-scale integration of graphene is of great importance in view of its numerous applications proposed or underway. A good graphene–silicon interface requires the fine control of several parameters and may turn into a high-cost material, suitable for the most advanced applications. Procedures that can be of great use for a wide range of applications are already available, but others are to be found, in order to modulate the offer of different types of materials, at different levels of sophistication and use. We have been exploring different electrochemical approaches over the last 5 years, starting from graphene oxide and resulting in graphene deposited on silicon-oriented surfaces, with the aim of understanding the reactions leading to the re-establishment of the graphene network. Here, we report how a proper choice of both the chemical environment and electrochemical conditions can lead to a more controlled and tunable graphene–Si(111) interface. This can also lead to a deeper understanding of the electrochemical reactions involved in the evolution of graphene oxide to graphene under electrochemical reduction. Results from XPS, the most suitable tool to follow the presence and fate of functional groups at the graphene surface, are reported, together with electrochemical and Raman findings.

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“…When looking at carbon materials, just recently it was demonstrated that alkali metal and earth alkaline metal cations have striking effect on the process of electrochemical reduction of graphene-oxide. 16 This process takes place at potentials where cations from supporting electrolyte cannot be reduced, so the effect was ascribed to the interaction of M + and M 2+ with oxygen functional groups, resulting with their activation towards the reduction process. Hence, one might expect that the effect of alkali metal cations from supporting electrolyte could be expected in some other cases, like ORR.…”

Section: Introductionmentioning

confidence: 99%

Effects of alkali metal cations on oxygen reduction on N-containing carbons viewed as the interplay between capacitive and electrocatalytic properties: Experiment and theory

Pašti

Dobrota

Gavrilov

et al. 2019

JSCS

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The development of new electrocatalysts for the oxygen reduction reaction (ORR) is crucial for the sustainable energy economy. Both fundamental understanding of surface processes under operating conditions and suitable ORR activity measurements are necessary to select the best electrocatalyst candidate. In the present study, to contribute to this matter, we show that both the nature of alkali metal cations (Li + , Na + and K +), composing supporting aqueous hydroxide solution, as well as the potential sweep rate in rotating disk electrode voltammetry measurements, influence the results of measurements of ORR activities of N-containing nanocarbons. Based on density functional theory calculations, we concluded that the specific interactions of hydrated cations with oxygen functional groups are responsible for such behaviour, leading to a close interplay between the electrode double layer charging and the parallel Faradaic process on carbon surface. From a practical point of view, the presented results indicate that it is necessary to standardize carefully the ORR measurements on different carbon materials.

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When supporting electrolyte matters – Tuning capacitive response of graphene oxide via electrochemical reduction in alkali and alkaline earth metal chlorides

Cited by 9 publications

References 36 publications

Charge Capacitance and Hydrogen Storage Capacity of Drop Cast and Electrodeposited Reduced Graphene Oxide Coatings

Charge Capacitance and Hydrogen Storage Capacity of Drop Cast and Electrodeposited Reduced Graphene Oxide Coatings

Effect of Electrolytic Medium on the Electrochemical Reduction of Graphene Oxide on Si(111) as Probed by XPS

Effects of alkali metal cations on oxygen reduction on N-containing carbons viewed as the interplay between capacitive and electrocatalytic properties: Experiment and theory

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