Reaction frequency of solvated electrons in water interacting with atmospheric-pressure helium plasma jet

Abstract

We employed the charge transfer to solvent (CTTS) transition of iodine negative ions to investigate the reactivity of solvated electrons in water interacting with an atmospheric-pressure helium plasma jet. A dye laser pulse at 225 nm was injected into the solution of potassium iodide, which was irradiated with an atmospheric-pressure helium plasma jet, and the reaction frequency of solvated electrons produced by the CTTS transition was measured by optical absorption spectroscopy. We observed the temporal and spatial variations of the reaction frequency of solvated electrons. We found that the reaction frequency of solvated electrons was determined by the concentrations of dissolved oxygen and hydrogen peroxide. We detected a high reaction frequency of solvated electrons in the limited depth region from the solution surface, indicating that hydrogen peroxide is localized near the plasma-liquid interface.