Silicon nanoparticles are formed from SiO2 particles by conducting plasma-induced cathodic discharge electrolysis. In a LiCl-KCl melt in which SiO2 particles were suspended at 450 degrees C, we obtained Si nanopartides with diameters around 20 nm. During the electrolysis period, SiO2 particles are directly reduced by discharge electrons on the surface of the melt just under the discharge, and the deposited Si atom clusters form Si nanoparticles, which leave the surface of the original SiO2 particle due to free spaces caused by a molar volume difference between SiO2 and Si. We also found that SiC nanoparticles can be obtained using carbon anode. Based on Faraday's law, the current efficiency for the formation of Si nanoparticles is 70%. (c) 2012 Elsevier Ltd. All rights reserved.