Electrodeposition of Metals

AlCl3-based ionic liquids (ILs) were the first to be used for the electrodeposition of metals. The electrodeposition of aluminum has enormous potential in industrial applications. The main reason for this is that aluminum reacts with oxygen to form dense layers of aluminum oxides, protecting metals from corrosion. This chapter focuses on the electrodeposition of refractory metals notably titanium (Ti), niobium (Nb), and tantalum (Ta) from room-temperature ILs (RTILs) and from high-temperature molten salts as well. RTILs are used as possible alternative electrolytes to investigate the electrodeposition of refractory metals, and some of the most useful physical properties of ILs are given in the chapter. The chapter also describes concisely the electrodeposition of chromium (Cr), molybdenum (Mo), and zirconium (Zr) from RTILs. It discusses how the composition of an IL determines in particular the first coordination shell around a metal solute ion, which in principle allows to control the redox potential of this species.