Electrochemical Growth of Single Crystal Alumina Nanoparticles Using Al³⁺ Ion Conducting Solid Electrolytes

Abstract

Single crystals of Al₂O₃ nanoparticles were successfully synthesized by dc electrolysis of the Al³⁺ ion conducting Al₂(WO₄)_2.4(MoO₄)_0.6 solid solution electrolyte at 11 V, 900°C. The particle size can be intentionally controlled by adjusting the electrolysis period: the particles distributed in the range of 100-900 nm, and the average size was 440 nm for 3 days electrolysis, while the range and the size became 100-1400 nm and 520 nm after the electrolysis for a week, respectively. Electron diffraction patterns for each particle evidenced that the particles grown were δ-Al₂O₃ because the present electrochemical method was applicable at moderate temperatures around 900°C.