The quantification of hydrogen peroxide (H₂O₂) generated in the plasma-liquid interactions is of great importance, since the H₂O₂ species is vital for the applications of the plasma-liquid system. Herein, we report on in situ quantification of the aqueous H₂O₂ (H₂O_2aq) using a colorimetric method for the DC plasma-liquid systems with liquid as either a cathode or an anode. The results show that the H₂O_2aq yield is 8–12 times larger when the liquid acts as a cathode than when the liquid acts as an anode. The conversion rate of the gaseous OH radicals to H₂O_2aq is 4–6 times greater in the former case. However, the concentrations of dissolved OH radicals for both liquid as cathode and anode are of the same order of tens of nM.

在等离子体-液体相互作用中产生的过氧化氢 (H ₂ O ₂ )的量化非常重要，因为 H ₂ O ₂物种对于等离子体-液体系统的应用至关重要。在此，我们报告了使用比色法对以液体作为阴极或阳极的 DC 等离子体-液体系统对水性 H ₂ O ₂ (H ₂ O _2aq ) 进行原位定量。结果表明，当液体作为阴极时，H ₂ O _2aq产率是液体作为阳极时的 8-12 倍。气态 OH 自由基向 H 的转化率₂ O _2aq是前一种情况的 4-6 倍。然而，作为阴极和阳极的液体，溶解的 OH 自由基的浓度都在几十 nM 的相同数量级。