In the D.C. Comics universe, Ion was created from the Green wavelength of the emotional spectrum, and was kept secret for eons. It gave the Green Lantern corps a portion of it's power. Ion was set free when Hal Jordan destroyed the Central Battery, and it chose Kyle Rayner as it's host.
Ion was also a character in the Marvel Comics Universe, where Ion was a super villain. Ion was the alias of Voletta Todd, a nuclear physicist who was turned into a cloud of ionized gas during an experiment gone wrong.
Ion was also the name of a short lived Japanese Manga published in 1997.
Since Ion is only one letter off from Ian, I think it would work as a first name. In 2011, 5 boys were named Ion.