Dysprosium electrodeposition from a hexaalkylguanidinium-based ionic liquid

Abstract

The rare-earth element dysprosium (Dy) is an important additive that increases the magnetocrystalline anisotropy of neodymium magnets and additionally prevents from demagnetizing at high temperatures. Therefore, it is one of the most important elements for high-tech industries and is mainly used in permanent magnetic applications, for example in electric vehicles, industrial motors and direct-drive wind turbines. In an effort to develop a more efficient electrochemical technique for depositing Dy on Nd-magnets in contrast to commonly used costly physical vapor deposition, we investigated the electrochemical behavior of dysprosium(iii) trifluoromethanesulfonate in a custom-made guanidinium-based room-temperature ionic liquid (RTIL). We first examined the electrodeposition of Dy on an Au(111) model electrode. The investigation was carried out by means of cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS). The initial stages of metal deposition were followed by in situ scanning tunneling microscopy (STM). CV measurements revealed a large cathodic reduction peak, which corresponds to the growth of monoatomic high islands, based on STM images taken during the initial stages of deposition. XPS identified these deposited islands as dysprosium. A similar reduction peak was also observed on an Nd-Fe-B substrate, and positively identified as deposited Dy using XPS. Finally, we varied the concentration of the Dy precursor, electrolyte flow and temperature during Dy deposition and demonstrated that each of these parameters could be used to increase the thickness of the Dy deposit, suggesting that these parameters could be tuned simultaneously in a temperature-controlled flow cell to enhance the thickness of the Dy layer.

DyF3: An Efficient Electrocatalyst for N2 Fixation to NH3 under Ambient Conditions

“…The rare‐earth element Dy is used in industries because of its high magnetic moment and the highest saturation magnetization of any element . It also shows excellent durability at high temperatures . These properties may be benefit for us to find efficient and durable NRR catalyst.…”

“…It is expected that the electrons movement in rare‐earth nanocrystals would be limited in two or/and all directions, which may reduce the competition of hydrogen evolution reaction (HER) during the electrolysis. The rare‐earth element Dy is used in industries because of its high magnetic moment and the highest saturation magnetization of any element . It also shows excellent durability at high temperatures .…”

Electrodeposition of a Rare‐Earth Iron Alloy from an Ionic‐Liquid Electrolyte

“…The electrodeposition of REEs and elements such as Fe, Ni or Co in the form of films from aqueous solutions has been reported. [8] However, this suggests that the electrodeposition of REEs from non-aqueous solvents might offer a promising alternative, [9] although it is recently reported that 0.4 wt.% of water in the electrolyte facilitate the deposition of Nd. This hydrogen then increases the pH of the solution, thereby favouring the formation of REE hydroxides and oxides.…”

Electrodeposition of Ag onto Au(111) from Deep Eutectic Solvents

“…[12] In particular, metals which are inaccessible from plating in aqueous solutions can efficiently be deposited with non-aqueous electrolytes/ionic liquids. [13,14] In contrast to ionic liquids, the components of a DES can easily be purified before mixing via established methods such as recrystallization or sublimation. In addition, most compounds are easily accessible, hence at low cost and environment-friendly.…”