A new negative ion generator using ZnO nanowire array

A nanoscale negative ion generator comprises a ZnO nanowire array as the cathode, a metal as the anode, and a high-voltage source. The tiny tips of the well-aligned ZnO nanowire array easily emit electrons, which combine with air ions to form negative ions. Air ions are molecular clusters consisting mostly of water molecules around a singly charged oxygen or nitrogen molecule. During this discharge, a faint purple corona appears on the nanowire tips in a dark room. Therefore, the tips of the ZnO nanowire to which a high voltage was applied generated an "ion wind" without a fan or any moving parts. An ion detector was used to count the negative ions. The new generator outperformed type. (c) 2006 The Electrochemical Society.