Silica nanowires were synthesized by using silica nanoparticles as a growth catalyst using a gas composed of CH4 and H-2 at 1050degreesC. Silica nanoparticles provide silicon and oxygen atoms for the formation of the nanowires, as well acting as a growth site. The nanowires nucleated on graphitic carbon layers formed around the seed particles, indicating that the nanowires grow by the vapor-solid mechanism. Photoluminescence spectra of the nanowires normally showed strong blue emission peaked at 3.1 and 2.8 eV under 3.8 eV laser excitation. Post-hydrogen annealing resulted in the appearance of longer wavelength photoluminescence band. (C) 2003 Elsevier B.V. All rights reserved.