LiNO3-Supported Electrodeposition of Metallic Nd from Nd-Containing Solvate Ionic Liquid

Inexpensive electrolyte systems and readily available rare-earth (RE) precursors are necessary for the facile recovery of RE metals at the lowest temperature, which will allow the sustainable development of RE metal-based industries. Inspired by previous reports on Nd electrodeposition in various expensive and specialized ionic liquids (ILs), herein, we developed a practical, green, and cost-effective Nd-containing solvate IL composed of an organic solvent [(1,3-dimethyl-2-imidazolidinone)] and Nd (CF3SO3)3; the IL is well suited for Nd electrodeposition using LiNO3. The electrolyte structure and electrochemical mechanism of the IL were elucidated through physicochemical analyses and cyclic voltammetry. The role of nitrate was investigated in detail. Nd was successfully electrodeposited using the proposed method, as confirmed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. Thus, this work provides a firm theoretical basis and a practical strategy for the cost-effective bulk electrochemical extraction of RE metals at relatively low temperatures.