Trivalent chromium electrodeposition using a deep eutectic solvent
Anti-Corrosion Methods and Materials
ISSN: 0003-5599
Article publication date: 14 September 2018
Issue publication date: 1 October 2018
Abstract
Purpose
This paper aims to investigate the electrolytic deposition of corrosion-resistant chromium coatings from a trivalent chromium plating bath based on deep eutectic solvent, a new generation of room temperature ionic liquids.
Design/methodology/approach
The electrolyte contained chromium (III) chloride, choline chloride and the additive of extra water. The surface morphology was estimated by means of SEM technique. The microstructure of as-deposited and annealed coatings was studied using X-ray diffraction method. The kinetics of the chromium electrodeposition and the corrosion electrochemical behavior of the coatings were investigated by cyclic voltammetry technique.
Findings
Chromium coatings with an amorphous type of microstructure are electroplated from this bath. Some carbon and oxygen are included in deposits obtained. The step-wise mechanism of the electrochemical reduction of Cr(III) ions to Cr(0) is detected. The current efficiency in this system sufficiently exceeds that typical of usual aqueous electrolytes. The coatings fabricated using plating bath based on deep eutectic solvent showed enhanced corrosion resistance in an acidic medium: there is no current peak of active dissolution in polarization curve and the corrosion potential shifts to more positive values as compared with “usual” chromium.
Originality/value
The electrodeposition of chromium coatings from an environmentally acceptable trivalent chromium electrolyte, a deep eutectic solvent containing chloride choline and extra water additive has been investigated for the first time.
Keywords
Acknowledgements
The authors thank Dr A.S. Baskevich for performing the XRD investigation and Dr S.A. Korniy for the preparation of SEM images. This work was supported by the Ministry of Education and Science of Ukraine (Project No. 0118U003398).
Citation
Protsenko, V., Bobrova, L. and Danilov, F. (2018), "Trivalent chromium electrodeposition using a deep eutectic solvent", Anti-Corrosion Methods and Materials, Vol. 65 No. 5, pp. 499-505. https://doi.org/10.1108/ACMM-05-2018-1946
Publisher
:Emerald Publishing Limited
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