An empirical equation for the dielectric constant in aqueous and nonaqueous electrolyte mixtures

Zuber, A.; Cardozo‐Filho, Lúcio; Cabral, Vladimir Ferreira; Checoni, Ricardo Figueiredo; Castier, Marcelo

doi:10.1016/j.fluid.2014.05.037

Cited by 20 publications

(21 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…39,40,48 By means of cyclic voltammetry (Figure S7), we have estimated the total capacitance (C t ) of MoS 2 /H 2 SO 4 to be about 20 μF cm −2 , which is even larger than the ECDL capacitances of MoS 2 with some ionic liquid electrolytes. 39,49 This might result from the relatively high dielectric constant (κ) of 0.5 M H 2 SO 4 (κ ≈ 70), 50 compared to that of ionic liquids (κ = 10−15). 40,51,52 The carrier density (n) doped by the H 2 SO 4 electrolyte gating can be estimated by n•q ≈ C t •V GS , 39,49 where q is the charge of a single electron.…”

Section: Nano Lettersmentioning

confidence: 99%

The Critical Role of Electrolyte Gating on the Hydrogen Evolution Performance of Monolayer MoS₂

Liu

Li²,

et al. 2019

Nano Lett.

View full text Add to dashboard Cite

According to density functional theory, monolayer (ML) MoS2 is predicted to possess electrocatalytic activity for the hydrogen evolution reaction (HER) that approaches that of platinum. However, its observed HER activity is much lower, which is widely believed to result from a large Schottky barrier between ML MoS2 and its electrical contact. In order to better understand the role of contact resistance in limiting the performance of ML MoS2 HER electrocatalysts, this study has employed well-defined test platforms that allow for the simultaneous measurement of contact resistance and electrocatalytic activity toward the HER during electrochemical testing. At open circuit potential, these measurements reveal that a 0.5 M H2SO4 electrolyte can act as a strong p-dopant that depletes free electrons in MoS2 and leads to extremely high contact resistance, even if the contact resistance of the as-made device in air is originally very low. However, under applied negative potentials this doping is mitigated by a strong electrolyte-mediated gating effect which can reduce the contact and sheet resistances of properly configured ML MoS2 electrocatalysts by more than 5 orders of magnitude. At potentials relevant to HER, the contact resistance becomes negligible and the performance of MoS2 electrodes is limited by HER kinetics. These findings have important implications for the design of low-dimensional semiconducting electrocatalysts and photocatalysts.

show abstract

Section: Nano Lettersmentioning

confidence: 99%

The Critical Role of Electrolyte Gating on the Hydrogen Evolution Performance of Monolayer MoS₂

Liu

Li²,

et al. 2019

Nano Lett.

View full text Add to dashboard Cite

show abstract

“…Some of them [20,21] are based on theories such as the Onsager [22] and Kirkwood theories [23]. Many empirical correlations were also proposed to represent the dependence on temperature [16,[24][25][26][27][28][29][30] and/or on density [14,15,31,32]. However, except for those developed in [24] for ethanol and in [26] for water, these correlations are limited to temperatures lower than 400K.…”

mentioning

confidence: 99%

An empirical correlation for the relative permittivity of liquids in a wide temperature range: Application to the modeling of electrolyte systems with a GE/EoS approach

Raspo

Neau

2020

Fluid Phase Equilibria

View full text Add to dashboard Cite

Relative permittivity, also known as static dielectric constant, is a key property of solvents in electrolyte solutions. It strongly influences the solubility of solutes and, therefore, it can be used as a predictive tool in chemical engineering processes. Relative permittivity also plays an essential role in the modeling of phase equilibria of electrolyte systems, since it is involved in the Debye-Hückel model and in the Mean Spherical Approximation, commonly used to represent long-range interactions between ions. In this paper, we propose a new temperature-dependent correlation for the relative permittivity of liquid water, methanol and ethanol, valid in a wide temperature range, including very high temperatures. Comparison with other literature equations evidenced that the main interest of the proposed correlation is to allow satisfactory predictions of the relative permittivity, not only in the range of validity of other literature models, but also in the high temperature domain, including supercritical temperatures for water. The new correlation is then used with the NRTL-PRA EoS to predict vapor pressure of water with several salts, including single electrolytes and two-salts mixtures; it must be noted that the modeling presented in this work is relevant for any G E /EoS model, since in this case (binary interactions between water and ions being equal to zero), the excess Gibbs energy reduces to the Long-Range term derived from the Pitzer-Debye-Hückel model. A temperaturedependent correction of the solvent relative permittivity is proposed to account for its dependence on ion mole fraction in this Long-Range term. Results thus obtained show that this correction leads to an accurate prediction both: for vapor pressures of aqueous electrolyte solutions in a very wide temperature domain and for the modeling of vapor-liquid equilibria of methanol-water and ethanolwater mixtures with several salts.

show abstract

“…( 14)). Literature values were used for solution permittivities [42] (Eq. ( 4), densities [43,44], and ionic radii [45,46],…”

mentioning

confidence: 99%

“…We begin by comparing the classical theory with recent experiments. Zuber et al [42] fitted permittivity data to the empirical formula,…”

mentioning

confidence: 99%

See 1 more Smart Citation

Simple Theory of Ionic Activity in Concentrated Electrolytes

Schlumpberger¹,

Bazant²

2017

Preprint

View full text Add to dashboard Cite

The Debye-Hückel formula for ionic activity coefficients is extended for concentrated solutions by solving a simple model of many-body Coulomb correlations and adding the Born solvation energy. Given the bulk permittivity, our formula is able to fit activity data for diverse electrolytes with only one parameter to adjust the correlation length, which interpolates between the Bjerrum length and the mean ion spacing. The results show that ionic activity in most electrolytes is dominated by three types of electrostatic forces: (i) mean-field charge screening, (ii) solvation, and (iii) Coulomb correlations, both "over-screening" (charge oscillations) and "under-screening" (extending beyond the Debye screening length).

show abstract

An empirical equation for the dielectric constant in aqueous and nonaqueous electrolyte mixtures

Cited by 20 publications

References 37 publications

The Critical Role of Electrolyte Gating on the Hydrogen Evolution Performance of Monolayer MoS₂

The Critical Role of Electrolyte Gating on the Hydrogen Evolution Performance of Monolayer MoS₂

An empirical correlation for the relative permittivity of liquids in a wide temperature range: Application to the modeling of electrolyte systems with a GE/EoS approach

Simple Theory of Ionic Activity in Concentrated Electrolytes

Contact Info

Product

Resources

About

An empirical equation for the dielectric constant in aqueous and nonaqueous electrolyte mixtures

Cited by 20 publications

References 37 publications

The Critical Role of Electrolyte Gating on the Hydrogen Evolution Performance of Monolayer MoS2

The Critical Role of Electrolyte Gating on the Hydrogen Evolution Performance of Monolayer MoS2

An empirical correlation for the relative permittivity of liquids in a wide temperature range: Application to the modeling of electrolyte systems with a GE/EoS approach

Simple Theory of Ionic Activity in Concentrated Electrolytes

Contact Info

Product

Resources

About

The Critical Role of Electrolyte Gating on the Hydrogen Evolution Performance of Monolayer MoS₂

The Critical Role of Electrolyte Gating on the Hydrogen Evolution Performance of Monolayer MoS₂