ZnO nanowire arrays were synthesized on Au-coated silicon (100) substrates by using vapour–liquid–solid process in this work. The effect of growth temperatures on the crystal structure and the surface morphology of ZnO nanowires were investigated by X-ray diffraction and scanning electron microscope. The absorption and optical characteristics of the nanowires were examined by Ultraviolet/Visible spectroscopy, and photoluminescence, respectively. The photoluminescence results exhibited ZnO nanowires had an ultraviolet and blue emission at 383 and 492nm. Then a nanogenerator with ZnO nanowire arrays was fabricated and demonstrated Schottky-like current–voltage characteristics.