Influence of discharge types on hydrogen peroxide generation in water with/without PI film barrier

Discharge types in water have great differences in morphology and physical properties which can play significant roles in active species production. The characteristics of different discharge types (streamer and spark discharge) and their influences on hydrogen peroxide (H₂O₂) generation are investigated in this paper. Three discharge regions i.e., streamer, streamer-to-spark and spark regions are divided according to the breakdown probability. The experimental results show that the discharges in streamer-to-spark region gain the highest production rate and energy yield of H₂O₂ generation. While we find that the streamer discharges just below the threshold of streamer and streamer-to-spark regions are more suitable for H₂O₂ generation considering the quick corrosion of electrodes caused by sparks. A layer of 0.1 mm polyimide (PI) film is introduced in the experiment, which efficiently inhibits the streamer-to-spark transition and proves to further promote the maximum production rate of H₂O₂ in streamer discharge from 2.6 to 3.5 μmol/(L·min) with 8% loss in energy yield.