A reactor for generating DC plasma inside a liquid

We present a plasma reactor able to generate DC discharge plasma inside an aqueous solution. The key point is that one wire electrode for the plasma generation is inside a capillary quartz tube, leaving a small gap between the electrode tip and the end of the capillary quartz tube. When the capillary quartz tube is immersed in an aqueous solution, a small gas gap is provided between the electrode tip and the solution. Discharge plasma can be generated at the gas gap, as applied DC voltage is beyond the gas breakdown voltage. As two examples among many possible applications, hydrogen peroxide and nitrate are synthesized from the plasma reactor with a flowing aqueous solutions of Na 2 SO 4 . Graphical abstract A plasma reactor is designed to generate DC discharge in an aqueous solution. H 2 O 2 , nitrate and nitrite can be formed by the plasma inside the aqueous solution.