Investigation of reactive species using various gas plasmas

Abstract

In this study, atmospheric nonequilibrium plasmas were generated with six gas species using a multi-gas plasma jet. Singlet oxygen, OH radicals, H radicals, and NO radicals, in reaction with a solution interface, were measured using electron spin resonance. Carbon dioxide plasma generated the largest amount (90 μM) of singlet oxygen at 30 s, and argon-containing vapor gas plasma generated the largest amount (210 μM) of OH radicals. Among the homo-atomic gas species, nitrogen plasma generated the largest amount (130 μM) of OH radicals. In addition, H radicals were generated with argon, helium, and nitrogen plasmas. NO radicals were generated with nitrogen–oxygen plasma, and the largest amount of NO radicals was generated at a 1 : 1 volume ratio. These measurement results of the reactive species generated by individual gas plasmas permit identification of the production processes of reactive species.