Formation and size control of titanium particles by cathode discharge electrolysis of molten chloride

Cathode discharge electrolysis of LiCl–KCl–K2TiF6 has been conducted under 1 atm of Ar. Near spherical particles consisting of metallic or partially oxidized titanium in the core and TiO2 in the surface layer were obtained. The Ti particles are originally formed in the melt by reduction of Ti ions, and a surface TiO2 layer is formed when the Ti particles are exposed to air or water. The particle sizes were in the range 10–400 nm, and were strongly dependent on electrolytic conditions, such as quantity of electricity, K2TiF6 concentration, bath temperature and current per melt volume. The particle growth mechanism was also investigated, and it was confirmed that reduction of ions at particle surfaces is involved in particle growth.