The effect of liquid conductivity on a helium plasma jet and the hydrogen peroxide production

作者：Edwin A. Oshin, Md Ziaur Rahman, Chunqi Jiang · 发表于：Physica Scripta · 年份：2025 · DOI：10.1088/1402-4896/adddf8 · 被引用次数：4 · 研究领域：Plasma Applications and Diagnostics、Vacuum and Plasma Arcs、Plasma and Flow Control in Aerodynamics

Abstract Understanding plasma-liquid interactions and the impact of the electrical conductivity ( σ ) of liquid on plasma is important for plasma applications in water treatment and medicine. Ultrapure water, phosphate-buffered saline (PBS) solution, biological media, and sodium chloride (NaCl) solutions at various concentrations were used in this study to provide a broad range of conductivity values ranging from 0.055 μS cm −1 to 222 mS cm −1 . A helium atmospheric pressure plasma jet (APPJ) impinging on liquid was generated in ambient air using a hollow-needle electrode that was powered by 200 ns, 7 kV pulses at a pulse repetition frequency of 1 kHz. Three regimes of the discharge energy consumption vs. σ were identified—low, high and transition, and are separated by two σ threshold values, 30.2 mS cm −1 and 69.5 mS/cm. For liquid with σ ≤ 30.2 mS cm −1 , the impinging plasma behaves as a typical guided streamer with a moderate energy per pulse (< 80 μJ) and a relative low H 2 O 2 production rate ( ≤ 0.22 nmol min −1 ml −1 ). For solutions with σ ≥ 69.5 mS/cm, the APPJ transitions to a different mode with 70 times more current peak and 4.8 times more energy per pulse compared with the low σ cases, and has enhanced production of excited species across the interelectrode gap. The H 2 O 2 production rate was found increasing monotonically with σ and the maximum value of 0.435 nmol min −1 ml −1 was obtained for σ = 222 mS cm −1 . Although the production rate incr...