Description of the physicochemical properties of a gas–liquid phase discharge under the Ar—N2 environment

AC-excited Ar—N2 gas–liquid phase discharges, operating at constant AC amplitude, are investigated as a function of the N2 concentration from 0 vol. % to 100 vol. % in an Ar—N2 mixture. Immediately after discharge initiation, increasing the N2 concentration in Ar significantly affects discharge voltage characteristics, optical-emission intensity, and rotational and vibrational temperatures. At a later stage, increasing the N2 concentration stimulates significant temporal behavior in discharge electrical characteristics such as the voltage and power input; discharge channel length in liquid; liquid properties such as pH and conductivity; and instantaneous concentrations of H2O2, NO2−, and NO3− in the liquid phase. Moreover, a temporal study of the aforesaid important experimental parameters indicates that in a given gas mixture, the length of the discharge channel and species concentrations are sensitive to the liquid properties. On the one hand, present experimental results are helpful in improving the understanding of physical–chemical processes of discharge in the gas–liquid phase. On the other hand, these are important to extend the practical applications of gas–liquid phase discharge in the field of environmental safety, plasma medicine, hydroponics, and so on.