Efficient and selectable production of reactive species using a nanosecond pulsed discharge in gas bubbles in liquid

A plasma gas bubble-in-liquid method for high production of selectable reactive species using a nanosecond pulse generator has been developed. The gas of choice is fed through a hollow needle in a point-to-plate bubble discharge, enabling improved selection of reactive species. The increased interface reactions, between the gas-plasma and water through bubbles, give higher productivity. H2O2 was the predominant species produced using Ar plasma, while predominantly NO3- and NO2 were generated using air plasma, in good agreement with the observed emission spectra. This method has nearly 100% selectivity for H2O2, with seven times higher production, and 92% selectivity for NO3-, with nearly twice the production, compared with a plasma above the water. A plasma gas bubble-in-liquid, with chosen gas, method is described. The gas of choice enables improved selection of reactive species and increased interface reactions enable higher productivity. "Ar" plasma produces a high concentration of H2O2, while "air" plasma produces high concentrations ofNO3- and NO2. The selectivity and productivity are much higher than with a plasma created above liquid.