Plasma characteristics of atmospheric pinhole discharge in water

Solution-phase synthesis needs rapid generation of high-density reactive species to initiate the chemical reaction. Here we report a novelty method to efficiently produce reactive species (including center dot H, center dot OH, center dot O, H2O2 and O-3) by atmospheric pinhole discharge in water. The plasma is initiated in bubbles generated by Joule heat on both sides of the pinhole leading to the increase of contact volume between the plasma and the liquid. The discharge type is similar to arc discharge, which can continuously act with liquids. The energy yield of reactive oxygen species in water can be attained to 1.5 g/kWh without the addition of O-2. In addition, the in-liquid pinhole discharge can be maintained at a relatively high solution conductivity over 1000 mu S/cm.