title: Degradation of methylene blue by radio frequency plasmas in water under ultraviolet irradiation.
abstract: The degradation of methylene blue by radio frequency (RF) plasmas in water under ultraviolet (UV) irradiation was studied experimentally. When the methylene blue solution was exposed to RF plasma, UV irradiation from a mercury vapor lamp enhanced degradation significantly. A lamp without power supply also enhanced degradation since weak UV light was emitted weakly from the lamp due to the excitation of mercury vapor by stray RF power. Such an enhancement is explained by the fact that after hydrogen peroxide is produced via the recombination process of OH radicals around the plasma, OH radicals reproduced from hydrogen peroxide via the photolysis process degrade methylene blue.
authors.affiliation: Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan. maehara@phys.sci.ehime-u.ac.jp
authors.forename: Tsunehiro
authors.initials: T
authors.lastname: Maehara
authors.forename: Kyohei
authors.initials: K
authors.lastname: Nishiyama
authors.forename: Shingo
authors.initials: S
authors.lastname: Onishi
authors.forename: Shinobu
authors.initials: S
authors.lastname: Mukasa
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Toyota
authors.forename: Makoto
authors.initials: M
authors.lastname: Kuramoto
authors.forename: Shinfuku
authors.initials: S
authors.lastname: Nomura
authors.forename: Ayato
authors.initials: A
authors.lastname: Kawashima
mesh_terms: D006861:Hydrogen Peroxide / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry / Q000528:radiation effects*; D011846:Radio Waves; D014466:Ultraviolet Rays; D014867:Water
chemical_list: D014867:Water; D006861:Hydrogen Peroxide; D008751:Methylene Blue