Formation of Si nanowires by the electrochemical reduction of porous Ni/SiO2 blocks in molten CaCl2

Silicon nanowires (SiNWs) were prepared by the electrochemical reduction of solid Ni/SiO2 blocks in molten CaCl2 at 1173 K. The SiNWs have diameter distributions ranging from 80 to 350 nm, and the nickel-silicon droplets are found on the tips of the nanowires. The growth mechanism of SiNWs was investigated, which confirmed that the nano-sized nickel-silicon droplets formed at the Ni/SiO2/CaCl2 three-phase interline. The droplets lead to the oriented growth of SiNWs. Formation of nano-sized nickel-silicon droplets suggests that this method could be a potential way to produce nano-sized metal suicides. (C) 2015 Elsevier Ltd. All rights reserved.