Cailiao Baohu (Aug 2024)
Research Progress of Chromium Electrodeposition from Deep Eutectic Solvents
Abstract
Metal chromium coating has been widely used as decorative and functional coatings in the metallurgical and chemical industries due to its high hardness， excellent corrosion resistance and aesthetic appearance.The traditional chromium electroplating process uses hexavalent chromium electroplating.However， hexavalent chromium electrolytes are highly toxic and strong carcinogens， which harm human health and seriously pollute the environment.Trivalent chromium electroplating is considered one of the most important and effective processes to replace hexavalent chromium electroplating.However， due to the limitations of aqueous solutions， trivalent chromium electroplating exhibits shortcomings such as hydrogen evolution， difficulty in thickening the coating and low current efficiency， which restrict its development.Seeking a new electrolyte system that can replace aqueous solutions has become one of the research directions for trivalent chromium electroplating.As a new type of green solvent， deep eutectic solvents (DESs) show great promise in the electrodeposition of metals due to their advantages， including ease of synthesis， high electrical conductivity， wide electrochemical window and good solubility.They overcome the shortcomings of the high volatility of organic solvents， the complex preparation process of ionic liquids and high costs.In this paper， the physicochemical properties of deep eutectic solvents used for chromium electrodeposition and the forms in which metal ions exist within them were introduced.The research progress on chromium and its alloys electrodeposition in DESs was reviewed.The effects of additives on chromium electrodeposition in DESs were discussed.Issues related to chromium electrodeposition in DESs were analyzed， and directions for further research were explored.
