Electrodeposition of copper from deep eutectic solvents by using pulse current

Cu electrodeposition is of great significance in various industries, such as electronics, sensors and aerospace. Electroplating is the main production process for the deposition of metallic Cu films. Traditionally the process was performed using aqueous solutions due to their convenience and low cost. However, such electrolytes suffer a number of drawbacks including poor deposit quality for some metals and pose serious environmental concerns, for example, when cyanide or chromium (VI) electrolytes are used. In addition, other metals with very negative reduction potentials, like aluminum and magnesium, cannot be plated from the aqueous solutions. Deep eutectic solvents, which are a type of room temperature molten salts, serve as the alternative and can overcome many of the limitations of aqueous solution.
The nature of the applied deposition current is another important factor. The application of direct current (DC) is the conventional method for plating metals. However, the deposit quality and metal properties are inadequate in many cases. One way of improving the deposits is by using additives, but these need to be monitored carefully to maintain performance. However, these issues can often be solved by applying pulse current (PC) without the use of additives. This research investigates the combined effects of using deep eutectic solvents and pulsed current deposition. The aim is to explore how they affect the morphology and microstructure of the metal deposit, with comparisons of the results to those obtained using aqueous solutions and direct current plating.