Abstract:Nanosized metallic silicon was prepared via molten salt electrolysis of SiO2. Effects of cell voltage on electrochemical reduction of SiO2 and microstructure of metallic silicon were investigated. The results suggest that higher cell voltage is in favor of electrochemical reduction of SiO2 with cell voltage varying from 1.7 V to 2.0 V. As cell voltage is operated under 1.8-2.0 V, SiO2 can be thoroughly electrolyzed to form metallic Si. Micro-structure of electro-produced Si is nanowire in the width of around 40 nm when cell voltage is 1.8 V. As cell voltage rises to 1.9 V, microstructure of silicon contains nanowire in the width of around 50 nm and nanosized particles with size of around 100 nm. As cell voltage is controlled at 2.0 V, microstructure of silicon is converted to accumulation of nanoparticles with size of 100-300 nm.