We report on the time dependent growth of vanadium pentoxide (V2O5) nanowires in V2O5 sols prepared from ammonium (meta)-vanadate in the presence of an acidic ion exchanger at different temperatures. V2O5 nanowires were adsorbed on SiO2/Si substrate pretreated with 3-aminopropyltriethoxysilane (3-APS) and the structural evolution at 24 degreesC was investigated by atomic force microscope (AFM) and scanning tunneling microscope (STM). Optical absorption and current-voltage measurements confirmed the gradual growth Of V2O5 nanowires with time. At the higher temperatures of the sol solution, the elongation rate of the V2O5 nanowires was enhanced, indicating the endothermic growth process. (C) 2004 Elsevier B.V. All rights reserved.