The influence of water on the cathodic voltammetric responses of choline chloride-urea and choline chloride-ethylene glycol deep eutectic solvents

Sudipta Roy, Priscila Estefania Valverde Armas, Mihael Bucko, Jelena B. Bajat

Research output: Contribution to conferencePoster

Abstract

During the last decade, choline chloride-based deep eutectic solvents (DESs) have been successfully used for electrodeposition of different metals (Cr, Mn, Cu, Ag, Fe, Zn) and alloys (ZnCr, Zn-Sn, Zn-Ni, Zn-Mn, Ni-Co etc.) on different substrates, producing films with characteristics that are completely different from those obtained from aqueous electrolytes. Yet, the processes which occur in the blank electrolytes during the cathodic polarization of the DESs, are still not completely understood. Besides, the role of water molecules in these cathodic processes, has not been investigated in detail. It is almost impossible to avoid the water presence during the electrodeposition of metal coatings from DESs. The water is absorbed due to the high hygroscopicity of DESs, but is also added with hydrated metal salts. This work aims to compare the cyclic voltammograms (CVs) of DESs of different compositions. The blank DESs were the mixtures of choline chloride with urea or with ethylene glycol. The CVs were recorded in electrolytes with various ratios of choline chloride, urea, ethylene glycol, and water. The increase in the concentration of a certain substance in DES results in the increase in the cathodic voltammetric peak or the cathodic current. So, it is possible to determine the species that are reduced preferentially from the mixture of the two or three substances. The measurements taken until now, have led us to assume interesting conclusions. Namely, the species which originate from urea, ethylene glycol or water, are reduced at more positive potential than choline chloride. Besides, it seems that the electrode potential where the reduction starts is the same for these three substances (urea, ethylene glycol and water), in case that they are analysed separately. However, when both urea and water (or both urea and ethylene glycol) are present in DES, their reduction does not occur at the same potential. Instead, the water (or ethylene glycol) reduction occurs at more positive potential, which is seen as the cathodic peak, while the urea reduction in this case is hindered (shifted to more negative potential).

Conference

Conference12th International Workshop on Electrodeposited Nanostructures
Abbreviated titleEDNANO-12
CountryBulgaria
CitySofia
Period16/03/1718/03/17
Internet address

Fingerprint

Ethylene Glycol
Choline
Eutectics
Urea
Water
Electrolytes
Electrodeposition
Metals
Metal coatings
Cathodic polarization
Salts
Electrodes
Molecules
Substrates
Chemical analysis

Keywords

  • deep eutectic solvents
  • electrodeposition
  • cyclic voltammograms
  • choline chloride
  • ethylene glycol
  • electrolytes

Cite this

Roy, S., Valverde Armas, P. E., Bucko, M., & Bajat, J. B. (2017). The influence of water on the cathodic voltammetric responses of choline chloride-urea and choline chloride-ethylene glycol deep eutectic solvents. Poster session presented at 12th International Workshop on Electrodeposited Nanostructures, Sofia, Bulgaria.
Roy, Sudipta ; Valverde Armas, Priscila Estefania ; Bucko, Mihael ; Bajat, Jelena B. / The influence of water on the cathodic voltammetric responses of choline chloride-urea and choline chloride-ethylene glycol deep eutectic solvents. Poster session presented at 12th International Workshop on Electrodeposited Nanostructures, Sofia, Bulgaria.
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title = "The influence of water on the cathodic voltammetric responses of choline chloride-urea and choline chloride-ethylene glycol deep eutectic solvents",
abstract = "During the last decade, choline chloride-based deep eutectic solvents (DESs) have been successfully used for electrodeposition of different metals (Cr, Mn, Cu, Ag, Fe, Zn) and alloys (ZnCr, Zn-Sn, Zn-Ni, Zn-Mn, Ni-Co etc.) on different substrates, producing films with characteristics that are completely different from those obtained from aqueous electrolytes. Yet, the processes which occur in the blank electrolytes during the cathodic polarization of the DESs, are still not completely understood. Besides, the role of water molecules in these cathodic processes, has not been investigated in detail. It is almost impossible to avoid the water presence during the electrodeposition of metal coatings from DESs. The water is absorbed due to the high hygroscopicity of DESs, but is also added with hydrated metal salts. This work aims to compare the cyclic voltammograms (CVs) of DESs of different compositions. The blank DESs were the mixtures of choline chloride with urea or with ethylene glycol. The CVs were recorded in electrolytes with various ratios of choline chloride, urea, ethylene glycol, and water. The increase in the concentration of a certain substance in DES results in the increase in the cathodic voltammetric peak or the cathodic current. So, it is possible to determine the species that are reduced preferentially from the mixture of the two or three substances. The measurements taken until now, have led us to assume interesting conclusions. Namely, the species which originate from urea, ethylene glycol or water, are reduced at more positive potential than choline chloride. Besides, it seems that the electrode potential where the reduction starts is the same for these three substances (urea, ethylene glycol and water), in case that they are analysed separately. However, when both urea and water (or both urea and ethylene glycol) are present in DES, their reduction does not occur at the same potential. Instead, the water (or ethylene glycol) reduction occurs at more positive potential, which is seen as the cathodic peak, while the urea reduction in this case is hindered (shifted to more negative potential).",
keywords = "deep eutectic solvents, electrodeposition , cyclic voltammograms , choline chloride , ethylene glycol, electrolytes",
author = "Sudipta Roy and {Valverde Armas}, {Priscila Estefania} and Mihael Bucko and Bajat, {Jelena B.}",
year = "2017",
month = "3",
day = "16",
language = "English",
note = "12th International Workshop on Electrodeposited Nanostructures, EDNANO-12 ; Conference date: 16-03-2017 Through 18-03-2017",
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Roy, S, Valverde Armas, PE, Bucko, M & Bajat, JB 2017, 'The influence of water on the cathodic voltammetric responses of choline chloride-urea and choline chloride-ethylene glycol deep eutectic solvents' 12th International Workshop on Electrodeposited Nanostructures, Sofia, Bulgaria, 16/03/17 - 18/03/17, .

The influence of water on the cathodic voltammetric responses of choline chloride-urea and choline chloride-ethylene glycol deep eutectic solvents. / Roy, Sudipta; Valverde Armas, Priscila Estefania; Bucko, Mihael; Bajat, Jelena B.

2017. Poster session presented at 12th International Workshop on Electrodeposited Nanostructures, Sofia, Bulgaria.

Research output: Contribution to conferencePoster

TY - CONF

T1 - The influence of water on the cathodic voltammetric responses of choline chloride-urea and choline chloride-ethylene glycol deep eutectic solvents

AU - Roy, Sudipta

AU - Valverde Armas, Priscila Estefania

AU - Bucko, Mihael

AU - Bajat, Jelena B.

PY - 2017/3/16

Y1 - 2017/3/16

N2 - During the last decade, choline chloride-based deep eutectic solvents (DESs) have been successfully used for electrodeposition of different metals (Cr, Mn, Cu, Ag, Fe, Zn) and alloys (ZnCr, Zn-Sn, Zn-Ni, Zn-Mn, Ni-Co etc.) on different substrates, producing films with characteristics that are completely different from those obtained from aqueous electrolytes. Yet, the processes which occur in the blank electrolytes during the cathodic polarization of the DESs, are still not completely understood. Besides, the role of water molecules in these cathodic processes, has not been investigated in detail. It is almost impossible to avoid the water presence during the electrodeposition of metal coatings from DESs. The water is absorbed due to the high hygroscopicity of DESs, but is also added with hydrated metal salts. This work aims to compare the cyclic voltammograms (CVs) of DESs of different compositions. The blank DESs were the mixtures of choline chloride with urea or with ethylene glycol. The CVs were recorded in electrolytes with various ratios of choline chloride, urea, ethylene glycol, and water. The increase in the concentration of a certain substance in DES results in the increase in the cathodic voltammetric peak or the cathodic current. So, it is possible to determine the species that are reduced preferentially from the mixture of the two or three substances. The measurements taken until now, have led us to assume interesting conclusions. Namely, the species which originate from urea, ethylene glycol or water, are reduced at more positive potential than choline chloride. Besides, it seems that the electrode potential where the reduction starts is the same for these three substances (urea, ethylene glycol and water), in case that they are analysed separately. However, when both urea and water (or both urea and ethylene glycol) are present in DES, their reduction does not occur at the same potential. Instead, the water (or ethylene glycol) reduction occurs at more positive potential, which is seen as the cathodic peak, while the urea reduction in this case is hindered (shifted to more negative potential).

AB - During the last decade, choline chloride-based deep eutectic solvents (DESs) have been successfully used for electrodeposition of different metals (Cr, Mn, Cu, Ag, Fe, Zn) and alloys (ZnCr, Zn-Sn, Zn-Ni, Zn-Mn, Ni-Co etc.) on different substrates, producing films with characteristics that are completely different from those obtained from aqueous electrolytes. Yet, the processes which occur in the blank electrolytes during the cathodic polarization of the DESs, are still not completely understood. Besides, the role of water molecules in these cathodic processes, has not been investigated in detail. It is almost impossible to avoid the water presence during the electrodeposition of metal coatings from DESs. The water is absorbed due to the high hygroscopicity of DESs, but is also added with hydrated metal salts. This work aims to compare the cyclic voltammograms (CVs) of DESs of different compositions. The blank DESs were the mixtures of choline chloride with urea or with ethylene glycol. The CVs were recorded in electrolytes with various ratios of choline chloride, urea, ethylene glycol, and water. The increase in the concentration of a certain substance in DES results in the increase in the cathodic voltammetric peak or the cathodic current. So, it is possible to determine the species that are reduced preferentially from the mixture of the two or three substances. The measurements taken until now, have led us to assume interesting conclusions. Namely, the species which originate from urea, ethylene glycol or water, are reduced at more positive potential than choline chloride. Besides, it seems that the electrode potential where the reduction starts is the same for these three substances (urea, ethylene glycol and water), in case that they are analysed separately. However, when both urea and water (or both urea and ethylene glycol) are present in DES, their reduction does not occur at the same potential. Instead, the water (or ethylene glycol) reduction occurs at more positive potential, which is seen as the cathodic peak, while the urea reduction in this case is hindered (shifted to more negative potential).

KW - deep eutectic solvents

KW - electrodeposition

KW - cyclic voltammograms

KW - choline chloride

KW - ethylene glycol

KW - electrolytes

UR - http://www.szfki.hu/ednano/BOOK-of-Abstracts-EDNANO-12.pdf

M3 - Poster

ER -

Roy S, Valverde Armas PE, Bucko M, Bajat JB. The influence of water on the cathodic voltammetric responses of choline chloride-urea and choline chloride-ethylene glycol deep eutectic solvents. 2017. Poster session presented at 12th International Workshop on Electrodeposited Nanostructures, Sofia, Bulgaria.