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Article

Examples of the Superiority of Ionic Liquids and Deep Eutectic Solvents over Aqueous Solutions in Electrodeposition Processes

by
Ashraf Bakkar
Department of Civil and Environmental Engineering, College of Engineering and Computers at Al-Lith, Umm Al-Qura University, Al-Lith 28425, Saudi Arabia
ChemEngineering 2025, 9(1), 16; https://doi.org/10.3390/chemengineering9010016
Submission received: 7 December 2024 / Revised: 28 January 2025 / Accepted: 6 February 2025 / Published: 12 February 2025
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Abstract

:
The current electrolytes used for metal electrodeposition mostly use aqueous solutions that limit the range and quality of possible coatings. Also, some of these solutions may contain toxic and corrosive chemicals. Thus, the importance of ionic liquids (ILs) and deep eutectic solvents (DES) becomes clear, as they can be used as green non-aqueous electrolytes for the electrodeposition of a range of reactive metals that are impossible to deposit in aqueous solutions and for the improved electrodeposition of metals that are deposable in aqueous solutions. This paper presents some examples of electrodeposition in ILs and DESs that are considered specific processes. Aluminum, as an active metal that it is impossible to electrodeposit in aqueous solution, was electrodeposited from a chloroaluminate IL. Moreover, the electrodeposition of Al was carried out in open air using a novel approach. Chromium was electrodeposited from a DES containing the environmentally friendly form of Cr (III) instead of toxic Cr (VI). Magnesium alloys, as water-sensitive substrates, were electroplated in an air and water-stable DES. Also, this paper discloses, for the first time, the procedure of pretreatment of Mg alloys for successful electroplating.

1. Introduction

The current techniques for metal electrodeposition use aqueous electrolytes and have been utilized for a very long time, with relatively minor improvements. The use of aqueous-based solutions limits the electrodeposition processes to particular metals, such as Zn, Cu, Ni, Cr, Sn, Ag, Au, and Pb, and their alloys. Moreover, some of these aqueous solutions are usually corrosive and may contain toxic chemicals [1,2,3].
Ionic liquids (ILs) are novel solvents with high potential for use in electrodeposition processes. As their name suggests, they consist only of ions. ILs have high electrical conductivity, good viscosity, and low volatility, and they are considered environmental-friendly non-toxic electrolytes [1,2,3,4].
ILs differ from conventional molten salts in that they are systems with melting points below 100 °C [4,5]. Many IL systems have melting points below or around the room temperature. Ionic liquids, in contrast to aqueous solutions, have much wider electrochemical windows, and the problems related to hydrogen discharge can be excluded. Having significantly wide electrochemical windows, the ionic liquids enable the electrodeposition of reactive metals that cannot be electrodeposited in aqueous solutions, such as Al, Ti, Mo, Nb, and W. Reactive metals are electrodeposited at potentials more negative than the potential at which hydrogen discharges, so the result is the evolution of hydrogen in aqueous solutions rather than the electrodeposition of the metal. Also, the absence of hydrogen evolution in IL electrolytes leads to the electroplating of smooth, dense, and adherent coating layers with high wear and corrosion resistance [3,4,5,6,7].
Ionic liquid systems can be classified into three generations, with increasingly higher air and water stability from the first to the third generation, as follows: (1) The 1st generation is well known as extremely hygroscopic chloroaluminate ionic liquids, which are composed of AlCl3 and various organic salts, such as 1-ethyl-3-methylimidazolium chloride “[EMIm]+Cl−”. These ILs have to be utilized in an inert-gas atmosphere due to their highly hygroscopic nature and sensitivity to oxygen [8,9]. (2) The 2nd generation of ILs is based on air- and water-stable anions like BF4− and PF6−, instead of reactive halides. Although these ILs are classified as the first air and water-stable ILs, their anions hydrolyze with prolonged exposure to humid atmosphere [10,11]. (3) The 3rd generation of ILs is based on more hydrolysis-resistant anions, such as [(CF3SO2)2N−], alkylsulfates, or alkylphosphates. These ILs are classified as hydrophobic, and have wide electrochemical windows of up to 6 V [12,13].
Deep eutectic solvents “DESs” are ionic liquid-like systems as they consist of molecular constituents [14]. Although Abbott et al. [15] named the first DESs they invented as ionic liquid analogous systems, Martins et al. [16] reported that DESs, unlike ILs, are mixtures and not novel compounds. It is eventually stated that counting DESs as ILs is an unaccepted overgeneralization [14,16,17]. DESs- based on mixtures of choline chloride and hydrogen bond donors such as urea, glycerol, amides, or carboxylic acids- are widely used for the electrodeposition of less active metals [18,19,20,21]. DESs are very stable in air and water, and can contain a few percentage of water, but they have narrower electrochemical windows of up to 2 V [18,19,20,21].
This paper presents some results of electrodeposition in ILs and DESs, which include the following: (1) an innovated method for the electrodeposition of Al in ambient atmosphere from a chloroaluminate IL “AlCl3/1-ethyl-3-methy-imadazolium chloride (EMIC)”, (2) the electrodeposition of Cr layers from environmentally friendly Cr(III) salt in a DES, and (3) the successful electroplating of magnesium alloys, which are considered water-sensitive substrates, in a DES.
Aluminum, a reactive metal that it is impossible to electrodeposit in aqueous solution, was deposited from the highly hygroscopic IL “AlCl3/EMIC” in air. This was conducted after the ionic liquid was prepared in a glove box and covered with a non-water-absorbable layer of decane. This stable organic compound, decane, did not interact with the ionic liquid [22].
The electrodeposition of chromium is traditionally carried out using a mixture of strong inorganic acids and Cr(VI) oxide. However, hexavalent chromium “Cr(VI)” is toxic, carcinogenic, and mutagenic, and consequently poses obvious danger to workers’ health [19,23,24,25]. This necessitates replacing Cr(VI) with the more environmentally friendly Cr(III) in Cr electrodeposition processes. Therefore, a mixture of choline chloride and chromium (III) chloride has been shown to form a DES that is air and moisture-stable. This DES was easy to prepare and relatively simple to handle, as shown in the experimental section.
Magnesium and its alloys are highly reactive, so electroplating in aqueous solutions is hazardous and Mg is counted as a water-sensitive substrate [26,27,28]. That is why DESs are important, as they can serve as non-aqueous electrolytes for electroplating. In the present study, a DES of “2 M choline chloride (ChCl):1 M urea” was utilized as a solvent for ZnCl2 in order to deposit Zn onto Mg alloys.

2. Materials and Methods

All electrodeposition experiments were performed in lab atmosphere outside glove box, using an electrochemical cell that consisted of the IL or DES-containing beaker, in which an anode sheet and a substrate sheet (cathode) were immersed. The substrate sheet used for electrodeposition experiments of Al and Cr was mild steel of grade A 516, with nominal wt% composition: 0.21 C, 0.55–0.98 Mn, 0.13–0.45 Si, 0.040 S, and 0.035 P. It was connected as the cathode electrode, and the anode electrode was an Al sheet for Al electrodeposition and Ag sheet for Cr electrodeposition. For electroplating Zn onto Mg substrates, a Pt sheet anode electrode was used. The distance between the anode and cathode electrodes was maintained at 35 mm. The anode and cathode electrodes were connected to the terminals of a Potenio–Galvanostat (model Wenking PGS 95), which was adapted to work as a galvanostat controlled by a personal computer to provide the required constant current. Prior to electrodeposition, mild steel substrate specimens were polished, pickled for 5 min in 10% HCl solution, rinsed with water and acetone, and dried.
For aluminum electrodeposition, the ionic liquid electrolyte was made by mixing 0.6 M of AlCl3 (Sigma-Aldrich, St. Louis, MO, USA, 99% purity) and 0.4 M of 1-ethyl-3-methy-imadazolium chloride (EMIC) “C6H11ClN2” (Sigma-Aldrich, ≥95% purity) via stirring in a small beaker inside a glove box which was full of argon gas. The mixture was converted completely into liquid in about 3 min. Then, a layer of n-decane “C10H22” (Sigma-Aldrich, ≥99% purity) was added, which floated on the ionic liquid that was formed. The decane acted as an insulating layer that prevents any interaction with air. This allowed the beaker containing the ionic liquid to be transported out of the glove box for electrodeposition experiments in open-to-air conditions. The beaker was covered by a polyvinyl chloride (PVC) sheet with slots for holding two aluminum sheets (80 × 10 × 1 mm) and a mild steel sheet (80 × 10 × 2 mm). The steel sheet was fixed between the Al sheets, keeping 15 mm from each Al sheet. The Al sheets were connected as anode and steel sheet was connected as cathode and both were immersed in electrolyte so that an area of (30 × 10 mm2, two sides) could be coated. For electroplating chemically Ag-coated polymer fibers of polyethylene terephthalate (PET), a bundle of fibers was suspended instead of the steel sheet between the Al sheets, and Al was potentiostatically electrodeposited using Al wire as a reference electrode. To show the coated and non-coated segments of polymer fibers with Al (using an optical microscope), the non-coated segment was painted with lacquer before the electrodeposition experiment.
For chromium electrodeposition, the DES electrolyte was prepared by mixing choline chloride (ChCl) “[(CH3)3NCH2CH2OH]+Cl−” (Sigma-Aldrich, ≥98% purity) and chromium (III) chloride hexahydrate “CrCl3·6H2O” (Molekula, ≥98% purity) with a stoichiometric eutectic mixture, in the mole ratio of 1:2, respectively. The mixture was gently heated to 60 °C. Lithium chloride “LiCl” (10% by weight) was added with continuous stirring to increase the conductivity of the IL electrolyte.
For electroplating of Mg substrates with Zn, the ionic liquid electrolyte was prepared by mixing 2 M of ChCl with 1 M of urea “CO(NH2)2”. The mixture was heated up to 90 °C until a clear colorless liquid was formed, and 0.5 M of ZnCl2 was then added with continuous gentle stirring until complete dissolution. The Mg alloy specimen was connected as a cathode and immersed in a 50 mL electrolyte at 60 °C. The procedure of the chemical pre-treatment of Mg and its alloys comprised the following three steps: (1) immersion in 10% NaOH aqueous solution for 5 min at 60 °C, (2) pickling in 125 g/L CrO3 + 110 mL/L HNO3 for 30 s at room temperature, and (3) fluoride activation in 380 mL/L HF (40%) for 10 min. The Mg alloy specimen was rinsed with distilled water after each step. Finally, the specimen was fixed with a copper screw bar and coated with lacquer, exposing a free surface of ~20 mm × 20 mm to be electroplated.
Microstructural investigations of the electrodeposited layers were undertaken using a scanning electron microscope “SEM” (model CamScan Series 4) equipped with an energy-dispersive X-ray analyzer (EDX). The investigations were conducted in the labs of Institut für Materialprüfung und Werkstofftechnik (Dr. Neubert GmbH), Clausthal, Germany.

3. Results and Discussion

3.1. Electrodeposition of Aluminum

Although there have been numerous publications on the successful electrodeposition of aluminum and its alloys in ionic liquids, industrial implementation has not been scaled. The electrodeposition process has to be carried out under an inert gas atmosphere inside a glove box where oxygen and moisture are kept near zero [29,30,31]. This demonstrates the importance of the novel approach presented in the current paper to conduct electrodeposition of Al in air, following to the preparation of ionic liquid inside a glove box and covering it with a hydrophobic layer of decane, which acts as a non-moisture-absorbable protective layer and has no reaction with the IL [22,32]. This example demonstrates the principal feasibility of further electrodeposition of Al in air outside the glove box.
A uniform, adherent, and fine-grained Al layer was electrodeposited at 5 mA/cm2 from EMIC/AlCl3 IL (40/60 mol%) on steel substrate; see Figure 1. The microstructure of the planar outer surface (Figure 1a) showed that the Al layer deposited at –5 mA/cm2 is extremely fine-micro-structured, with a mean particle size of 0.176 ± 0.026 µm (Figure 1d). The cross-sectional micrograph showed good adhesion of the Al layer with the steel substrate (Figure 1b). Also, the EDX spectra of the deposited layer (Figure 1c) showed that its composition is pure aluminum. Ultra fine micro-structured, and sometimes nanocrystalline Al layers, were reported to be electrodeposited from chloroaluminate ILs at higher current densities [29,33].
In order to attain stronger adhesion between the steel substrate and the Al layer, the steel substrate underwent insitu etching in the ionic liquid electrolyte just prior to Al electrodeposition. The in-situ etching was implemented through reversing the polarity of the electrodeposition cell; steel was connected as the anode with feeding of 2 mA/cm2 for 30 s, and then the electrodeposition of Al was conducted immediately. The anodic polarization of the steel substrate prior to aluminum deposition was shown to activate the steel substrate and resulted in excellent adhesion to aluminum layers [29,32]. Adhesion, a greatly important property, especially for applications requiring high corrosion resistance, was investigated by scratching the electrodeposited aluminum layer. The Al layer had excellent adhesion to the steel substrate, so that the scratch on the outer surface layer didn’t lead to flaking of the Al coat (Figure 2a). At the center of the scratch groove, the Al layer was still adherent, as detected by the EDX spectrum shown in Figure 2b.
As well as being used for electrodeposition in the lab atmosphere, the new procedure has also been successfully used to electroplate chemically Ag-coated polyethylene terephthalate (PET) polymer fibers with aluminum. Figure 3 shows PET fibers electroplated by Al for 30 min at 500 mVvs Al. Coating fibers with aluminum is of great interest and this procedure could be used for textiles used where heat and light reflection is required, e.g., for the synthesis of firefighter coats. Electroplating fibers with Al in an ambient atmosphere has the potential to replace the sputtering and spraying techniques used for all-over fabric coatings, which may produce Al layers with weak adhesion.

3.2. Electrodeposition of Chromium

Initial experiments on the electrodeposition of Cr from the DES “1 ChCl:2 CrCl3·6H2O + 10%LiCl” illustrated that successful Cr deposition is very responsive to slight variations in the electrodeposition parameters. However, galvanostatic electrodeposition at a current density (CD) of −0.5 mA/cm2 produced a dense, sealed, and adherent chromium layer (Figure 4) with a matte black color. The energy-dispersive X-ray (EDX) spectrum obtained from the deposited Cr layer (Figure 4c) revealed that the main element found in the coat is Cr. A significant peak of O was also observed; the oxygen detected in the electrodeposited black Cr layer is attributed to the reaction between Cr and the oxygen in air, forming a chromium oxide film [34,35,36]. The chloride compound present in the electrolyte might trace the coat surface with a chlorine element that is notably seen in the EDX spectrum. The presence of O and a small amount of residual Cl was previously reported in the black Cr layer electrodeposited from ChCl-containing DES [19,24,34,35]. The particle size distribution histogram of the electrodeposited Cr layer (Figure 4c) shows that the Cr particles are fine, with a mean particle size of 0.701 ± 0.102 µm.

3.3. Electroplating of Magnesium as a Water-Sensitive Substrate

Magnesium electroplating in aqueous solutions is hazardous because of the high activity of magnesium, and hence, magnesium and its alloys are considered water-sensitive substrates. Therefore, DESs were suggested for use as electrolytic solvents for electrodeposition onto Mg and its alloys. The corrosion current density (Icorr), measured by the potentiodynamic polarization technique, showed that the Icorr of Mg in the DES “ChCl/urea” is lower than that in the aqueous electrolyte by more than 7000 times [26]; see Table 1.
Ten Mg alloys were investigated as substrates for electroplating with Zn from the electrolyte “2 M ChCl:1M urea + 0.5 M ZnCl2” at a constant cathodic current density (CD) of −5 mA/cm2. Table 2 summarizes the results of electrodeposition experiments. Adherent Zn layers were successfully electrodeposited onto RE-Mg alloys, except for AE42. Consequently, it can be stated that RE-Mg alloys, free of Al, are more appropriate than all other Mg alloys tested as a substrate for the successful electrodeposition of adherent Zn layers. A key aspect of successful plating is the state of the Mg outer surface, which should be free of any oxide or compound that may prevent the adhesion of the electrodeposited Zn layer. It seems that the three-step chemical pretreatment of Mg alloys, as demonstrated in the experimental section, succeeded in activating the outer surface of Al-free Mg alloys, making them MgF2 instead of MgO. On the other hand, the Al-containing Mg alloys may resist etching and activation solutions and still have an oxide surface that prohibits adhesion with the electrodeposited Zn. More investigations are recommended to study the effect of chemical pre-treatment on the Mg surface.
The application of a constant cathodic current (5 mA/cm2) deposited dense, compact, and adherent Zn layers. The deposited Zn layer was dull and its microstructure (Figure 5a) shows that the Zn particles were deposited in the shape of a sharp-edged parallelogram, with an average particle size of 11.027 ± 0.354 µm (Figure 5b). The surface topography and roughness profile showed that the Zn layer deposited at a constant current is rough, with an arithmetical mean roughness “Ra” of 0.087 µm. However, the application of a pulsed cathodic current (between −5 mA/cm2 and 0.0 mA/cm2 at the loop 2 s on-time–1 s off-time) produced a smooth, shiny, and dense Zn layer (Figure 6a). The pulsed current increased the nucleation rate of deposited Zn particles at the expense of the growth rate [37,38], resulting in a finer particle size, with an average of 7.521 ± 0.484 µm (Figure 6c), and a smoother Zn layer with relatively lower roughness, Ra = 0.035 µm (Figure 6d). The cross-sectional micrograph (Figure 6b) reveals that the Zn layer is adherent to the Mg alloy substrate.
Corrosion testing through the potentiodynamic polarization in NaCl solution was used to investigate the cohesion and compaction of the Zn coatings, where the presence of any defect, like microcracks or fine pores in the coat, allows the Cl-containing solution to reach the Mg substrate; therefore, the eventual corrosion potential “Ecorr” is mostly characteristic of Mg and the corrosion current density “Icorr” is greatly high due to galvanic corrosion arising at the Mg-Zn interface [39,40]. Figure 7 shows that the potentiodynamic polarization of the Zn coat, deposited at a pulsed current, in 0.1 M NaCl solution, depicted a noble corrosion behavior similar to that of pure zinc. This proves that the Zn layer deposited at the pulsed current is adherent, sealed, compact, and free of defects.

4. Conclusions

The paper presented three examples of electrodeposition processes, showing the superiority of ionic liquids and deep eutectic solvents over aqueous solutions. These examples include the following: (1) the electrodeposition of Al, a metal impossible to deposit in aqueous solutions, (2) the electrodeposition of Cr from a new environmentally friendly electrolyte, and (3) the electroplating of Mg as a difficult-to-electroplate substrate in aqueous solutions. The obtained results can be concluded as follows:
-
Uniform, adherent, and shiny pure aluminum layers were successfully electrodeposited from a highly hygroscopic chloroaluminate ionic liquid “AlCl3/EMIC (60/40 mol%)” outside a glove box in ambient atmosphere, after protecting the chloroaluminate IL with a decane layer. The electrodeposition process was also successfully preceded for Al plating of Ag-coated polymer fibers.
-
The successful electrodeposition of dense and crack-free chromium layers was achieved using a green DES “1 ChCl:2 CrCl3·6H2O + 10%LiCl”, which contains chromium as an environmentally friendly cation “Cr(III)”.
-
An air and water-stable DES “1 ChCl:2 urea” was successfully used to electrodeposit adherent zinc layers on RE-Mg alloys. The Zn coats deposited at pulsed current densities were smooth, compact and free of crevices, and thus were protective against corrosion in Cl-containing aqueous solutions.

Funding

This research work was funded by Umm Al-Qura University, Saudi Arabia under grant number: 25UQU4331139GSSR01.

Data Availability Statement

The author confirms that the data supporting the findings of this study are available within the article and the associated references.

Acknowledgments

The author extends his appreciation to Umm Al-Qura University, Saudi Arabia for funding this research work through grant number: 25UQU4331139GSSR01.

Conflicts of Interest

The author declares no conflict of interest.

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Figure 1. (a) SEM micrograph of AL layer electrodeposited onto mild steel from EMIC/AlCl3 IL at CD = −5mA/cm2 for 1 h; (b) BS SEM cross-sectional micrograph of AL layer deposited onto a mild steel sheet; (c) EDX spectrum of the complete area of the electrodeposited AL layer revealed in (a); (d) Particle size distribution histogram of the electrodeposited AL layer.
Figure 1. (a) SEM micrograph of AL layer electrodeposited onto mild steel from EMIC/AlCl3 IL at CD = −5mA/cm2 for 1 h; (b) BS SEM cross-sectional micrograph of AL layer deposited onto a mild steel sheet; (c) EDX spectrum of the complete area of the electrodeposited AL layer revealed in (a); (d) Particle size distribution histogram of the electrodeposited AL layer.
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Figure 2. (a) SEM micrograph of the groove scratched mechanically on the Al-coated steel specimen; (b) EDX spectrum for point X, shown in the SEM micrograph in (a).
Figure 2. (a) SEM micrograph of the groove scratched mechanically on the Al-coated steel specimen; (b) EDX spectrum for point X, shown in the SEM micrograph in (a).
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Figure 3. (a) Optical micrograph showing coated and non-coated segments of polymer fibers with Al; the non-coated segment was previously coated with lacquer before the electrodeposition experiment; (b) SEM micrograph of Al-electroplated fiber.
Figure 3. (a) Optical micrograph showing coated and non-coated segments of polymer fibers with Al; the non-coated segment was previously coated with lacquer before the electrodeposition experiment; (b) SEM micrograph of Al-electroplated fiber.
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Figure 4. (a) SEM micrograph of the Cr thin layer, electrodeposited from “1 ChCl:2 CrCl3·6H2O” DES with 10% LiCl onto a mild steel sheet at CD = −0.5 mA/cm² and T = 60 °C for 2 h; (b) BS SEM cross-sectional micrograph of the Cr thin layer deposited onto a mild steel sheet; (c) EDX spectrum of the complete area of the Cr layer revealed in (a); (d) Particle size distribution histogram of the electrodeposited Cr layer.
Figure 4. (a) SEM micrograph of the Cr thin layer, electrodeposited from “1 ChCl:2 CrCl3·6H2O” DES with 10% LiCl onto a mild steel sheet at CD = −0.5 mA/cm² and T = 60 °C for 2 h; (b) BS SEM cross-sectional micrograph of the Cr thin layer deposited onto a mild steel sheet; (c) EDX spectrum of the complete area of the Cr layer revealed in (a); (d) Particle size distribution histogram of the electrodeposited Cr layer.
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Figure 5. (a) SEM micrograph, (b) particle size distribution histogram, and (c) surface topography micrograph and roughness profile of Zn layer electrodeposited in the DES “1 ChCl:2 urea” at a constant current density of −5 mA/cm2 and 60 °C for 1 h.
Figure 5. (a) SEM micrograph, (b) particle size distribution histogram, and (c) surface topography micrograph and roughness profile of Zn layer electrodeposited in the DES “1 ChCl:2 urea” at a constant current density of −5 mA/cm2 and 60 °C for 1 h.
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Figure 6. (a) SEM micrograph, (b) SEM cross-sectional micrograph, (c) particle size distribution histogram, and (d) surface topography micrograph and roughness profile of Zn layer electrodeposited at a pulsed current density of −5 mA/cm2 (2 s on-time–1 s off-time) and 60 °C for 1 h.
Figure 6. (a) SEM micrograph, (b) SEM cross-sectional micrograph, (c) particle size distribution histogram, and (d) surface topography micrograph and roughness profile of Zn layer electrodeposited at a pulsed current density of −5 mA/cm2 (2 s on-time–1 s off-time) and 60 °C for 1 h.
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Figure 7. Potentiodynamic polarization diagrams of WE43-T6 Mg alloy substrate, Zn-coated WE43-T6 Mg alloy, and Zn sheet in 0.1 M NaCl solution.
Figure 7. Potentiodynamic polarization diagrams of WE43-T6 Mg alloy substrate, Zn-coated WE43-T6 Mg alloy, and Zn sheet in 0.1 M NaCl solution.
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Table 1. Corrosion current density (Icorr) values of pure Mg in classical aqueous solution for Zn electrodeposition and in DES ionic liquid “ChCl/urea”.
Table 1. Corrosion current density (Icorr) values of pure Mg in classical aqueous solution for Zn electrodeposition and in DES ionic liquid “ChCl/urea”.
ElectrolyteIcorr (µA/cm²)
Classical aqueous acid chloride Zn plating solution
(150 g/L KCl and 23 g/L H3BO3), 25 °C		3711.17
“1 M ChCl:2 M urea” DES, 60 °C0.48
Table 2. Mg alloys investigated as substrates for electroplating with zinc.
Table 2. Mg alloys investigated as substrates for electroplating with zinc.
AlloyNominal Chemical Composition, wt.%Quality of Deposit
Cp Mg99.99 MgPD 1
AZ313 Al, 1 Zn, 0.2 MnPD
AZ616 Al, 3 Zn, 0.15 MnPD
AZ918.7 Al, 0.7 Zn, 0.13 MnPD
AS414.37 Al, 0.93 Si, 0.35 MnPD
WE43-T64 Y, 3.4 REAL 2
QE222.5 Ag, 2.1 REAL
MgGd5Sc14.64 Gd, 0.26 Sc, 1.53 MnAL
MgY4Sc13.88 Y, 0.73 Sc, 1.11 MnAL
AE424 Al, 2.5 RE, 0.1 MnPD
1 Powdery deposit; 2 Adherent layer.
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Bakkar, A. Examples of the Superiority of Ionic Liquids and Deep Eutectic Solvents over Aqueous Solutions in Electrodeposition Processes. ChemEngineering 2025, 9, 16. https://doi.org/10.3390/chemengineering9010016

AMA Style

Bakkar A. Examples of the Superiority of Ionic Liquids and Deep Eutectic Solvents over Aqueous Solutions in Electrodeposition Processes. ChemEngineering. 2025; 9(1):16. https://doi.org/10.3390/chemengineering9010016

Chicago/Turabian Style

Bakkar, Ashraf. 2025. "Examples of the Superiority of Ionic Liquids and Deep Eutectic Solvents over Aqueous Solutions in Electrodeposition Processes" ChemEngineering 9, no. 1: 16. https://doi.org/10.3390/chemengineering9010016

APA Style

Bakkar, A. (2025). Examples of the Superiority of Ionic Liquids and Deep Eutectic Solvents over Aqueous Solutions in Electrodeposition Processes. ChemEngineering, 9(1), 16. https://doi.org/10.3390/chemengineering9010016

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