Study on the Mechanism of Active Particle Generation and Energy Consumption in Pulse Pin-to-Water Discharge

Plasma-liquid interaction has enabled various innovative applications such as synthesis of green and sustainable ammonia and hydrogen energy resources. However, the chemical kinetics of active particles under plasma-stimulated evaporation is not well understood. In this study optical emission spectroscopy (OES) was performed to characterize gaseous active particles in three discharge regions. A zero-dimensional (0D) model was then employed to investigate key generation and transformation pathways of primary species, along with the influence of pulse width on peak density and energy efficiency near the liquid surface. The modeling results reveal that water vapor adjacent to the liquid surface enriches the reaction pathways of interfacial particles. The response of peak densities to pulse width variation differed among species: OH, O, and HO2 showed moderate increases, while H2O2 demonstrates a slight decrease at longer pulse widths. However, the energy efficiency for generating OH and O decreases with increasing pulse width, while the efficiency for HO2 and H2O2 improved slightly at pulse width of 2 μs.