An air ioniser (or negative ion generator or Chizhevsky's chandelier) is a device that uses high voltage to ionise (electrically charge) air molecules. ... Cations are positive ions missing one or more electrons, resulting in a net positive charge. Some commercial air purifiers are designed to generate negative ions.Ion generators use high voltage to electrically charge air molecules. Negative ions are particles with one or more extra electrons.When you turn on the ionizer the negatively charged air molecules will attach to the particles and then attach to or “plate out” to the walls, ceilings and any other surface