Influence of Fluid Dynamics on the Electrochemical Deposition of Tantalum

Abstract

In the electrochemical deposition of Tantalum from ionic liquids at moderate temperatures, the preparation of purely metallic coatings with thicknesses in the micrometer range and the accurate control of the crystallographic parameters remain challenging. In this work, preliminary experiments on the influence of fluid dynamics during the electrodeposition of tantalum in the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide using ultrasound as an additional source of energy were carried out. This included a study on the influence of the ultrasound amplitude on the deposition rate of tantalum by using cyclic voltammetry and the in-situ electrochemical quartz crystal microbalance technique.

(Invited) Ultrasound Application and Multi-Step Reactions in Electrodeposition of Refractory Metals

“…As we use a passive measurement method, the method can be applied even in the presence of ultrasound. This had been demonstrated in detail for aqueous solutions (51)(52)(53)(54)(55) and recently also for ILs (45). In related work, we studied the electrochemical reduction of NbCl 5 in BMP TFSI using the EQCM technique.…”

“…In the following, also the influence of ultrasound on the deposition of tantalum at room temperature was studied. In earlier work, it had been shown that ultrasound has both a positive effect in voltammetry and during potentiostatic experiments (45). However, those experiments had been carried out without any cooling.…”

“…In ILs, this implies potential issues with electrolyte stability, and the risk of forming impurities that can interfere with the electrode processes (38). There are a several reports on application of ultrasound in ionic liquids (39)(40)(41)(42)(43)(44)(45)(46)(47)(48). Already in 2003, Oxley et al studied the influence of acoustic cavitation on several ILs, including butylmethylimidazolium chloride (BMIm-Cl), by sonication with 20 KHz ultrasound at temperatures of 85 °C and 135 °C (39).…”

“…Several reports use US for sonochemical synthesis or simple dispersion of reactants in ILs as the solvent (46)(47)(48). Application of US to metal deposition from ILs has been scarce; examples are the electrodeposition of aluminum (44) and, from our own research, tantalum (45).…”