Ion Interactions across Graphene in Electrolyte Aqueous Solution

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F19%3A73597234" target="_blank" >RIV/61989592:15310/19:73597234 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.acs.org/doi/pdf/10.1021/acs.jpcc.8b12055" target="_blank" >https://pubs.acs.org/doi/pdf/10.1021/acs.jpcc.8b12055</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcc.8b12055" target="_blank" >10.1021/acs.jpcc.8b12055</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Ion Interactions across Graphene in Electrolyte Aqueous Solution

Popis výsledku v původním jazyce

The interfacial behavior of graphene is involved in a number of technological processes and applications, ranging from energy storage to sensing and nanofluidics. The organization of ions and structuring of water molecules close to a graphene interface, which represents an atomically thin surface, substantially affect the interfacial physicochemical properties in electrolytes as well as the specific capacitance of supercapacitors. Moreover, adsorption of ions on one side of the ultimately thin material may largely impact the adsorption of additional charge carriers on the opposite side and thus influence the overall supercapacitor performance. However, these phenomena are so far not fully understood. In this study, all-atomic classical molecular dynamics (MD) simulations were conducted with explicitly included polarization, which is essential for accurate description of electrolytes at interfaces in systems containing carbon allotropes. We employed an isotropic polarization model using classical Drude oscillators and adjusted Thole parameters for graphene. This approach improved the classical description of graphene-electrolyte interaction although did not fully cover the inherent anisotropy of graphene polarization because the field components parallel to the graphene sheet were largely reduced but not completely screened as in semimetals. The MD simulations were applied to examine the interface between graphene and potassium halide solutions. The results showed that water molecules formed a well-organized single layer on both sides of graphene, which primarily acted as a hydrophobic structuring agent. This arrangement significantly contributed to effective shielding of ion-ion interactions acting through the graphene sheet. Thus, the ion-specific structuring of adjacent electrolytes on opposing sides of graphene was generally independent. The findings help to understand structuring of electrolyte on graphene-based electrode materials of supercapacitors.

Název v anglickém jazyce

Ion Interactions across Graphene in Electrolyte Aqueous Solution

Popis výsledku anglicky

The interfacial behavior of graphene is involved in a number of technological processes and applications, ranging from energy storage to sensing and nanofluidics. The organization of ions and structuring of water molecules close to a graphene interface, which represents an atomically thin surface, substantially affect the interfacial physicochemical properties in electrolytes as well as the specific capacitance of supercapacitors. Moreover, adsorption of ions on one side of the ultimately thin material may largely impact the adsorption of additional charge carriers on the opposite side and thus influence the overall supercapacitor performance. However, these phenomena are so far not fully understood. In this study, all-atomic classical molecular dynamics (MD) simulations were conducted with explicitly included polarization, which is essential for accurate description of electrolytes at interfaces in systems containing carbon allotropes. We employed an isotropic polarization model using classical Drude oscillators and adjusted Thole parameters for graphene. This approach improved the classical description of graphene-electrolyte interaction although did not fully cover the inherent anisotropy of graphene polarization because the field components parallel to the graphene sheet were largely reduced but not completely screened as in semimetals. The MD simulations were applied to examine the interface between graphene and potassium halide solutions. The results showed that water molecules formed a well-organized single layer on both sides of graphene, which primarily acted as a hydrophobic structuring agent. This arrangement significantly contributed to effective shielding of ion-ion interactions acting through the graphene sheet. Thus, the ion-specific structuring of adjacent electrolytes on opposing sides of graphene was generally independent. The findings help to understand structuring of electrolyte on graphene-based electrode materials of supercapacitors.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Physical Chemistry C

ISSN

1932-7447

e-ISSN

—

Svazek periodika

123

Číslo periodika v rámci svazku

15

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

8

Strana od-do

9799-9806

Kód UT WoS článku

000465488600017

EID výsledku v databázi Scopus

2-s2.0-85064356258