Tailoring H₂O₂ production of atmospheric pressure plasma jets using various excitation mechanisms

Atmospheric pressure plasma jets (APPJs) are widely used in research and for application purposes. Different designs of APPJs exist, varying in geometry and excitation mechanism. A direct comparison of these APPJs is challenging, as the different geometries and particular excitation mechanisms strongly influence the plasma chemistry. To overcome this challenge, an APPJ equipped with a capillary was used, which is operable at various excitation mechanisms, including kHz pulsing with high voltage pulses having µs or ns rise time or using sinusoidal voltage pulses at 13.56 MHz [1]. The production of H₂O₂ by the APPJ was investigated as a model system since H₂O₂ is used in various application fields. The effect of the excitation mechanisms on the production of H₂O₂ was analyzed by treating liquids due to the high solubility of H₂O₂. The liquid H₂O₂ concentrations were measured by spectrophotometry. An increased humidity admixture and higher plasma powers enhance H₂O₂ production under all excitation mechanisms. The fast ns pulses and the RF operation show similar results up to plasma powers of 1.5 W, while the µs operation is less effective. The operation window for the excitation with ns pulses regarding the plasma power was increased to extend the application window of the APPJ, showing similar characteristics to those under RF operation at elevated plasma powers.

This work is supported by the DFG within CRC 1316 (subproject B11, project number 327886311).

[1] S. Schüttler et al 2025 J. Phys. D: Appl. Phys. 58 025203