Preparation and characterization of amorphous SiO2 nanowires

Amorphous SiO2 nanowires were prepared by heating Si powder and Au-coated Si(1 1 1) substrates for different times. The SiO2 nanowires were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results show that large amounts of amorphous SiO2 nanowires with a diameter of about 40 nm were formed on the entire surface of the substrates. Au particles were observed at the tip of the SiO2 nanowires, which is consistent with the well-known vapor-liquid-solid (VLS) process. It is found that the annealing time affects the morphology of the products. Finally, the growth mechanism of the SiO2 nanowires was discussed. (C) 2010 Elsevier B.V. All rights reserved.