Chemical reactions in liquid induced by atmospheric-pressure dc glow discharge in contact with liquid

We experimentally investigated some of the initial reactions in a liquid induced by electron or positive-ion irradiation from an atmospheric-pressure dc glow discharge in contact with the liquid. Aqueous solutions of NaCl, AgNO 3 , and HAuCl 4 are used as the electrolyte. We measured the pH and conductivity in the liquid at approximately 1 cm below the solution surfaces. OH radical generation in the liquid was observed by a chemical probe method. Experimental results showed that electron irradiation of the liquid surface generates OH − in water and that positive-ion irradiation of the liquid surface generates H + in water even without the dissolution of gas-phase nitrogen oxide. A possible reaction process is qualitatively discussed. In particular, the contribution of charge transfer collision between impinging low-energy positive ions and water molecules to the ionic species in the liquid is used to explain the overall tendency of the experimental results.