Generation of reactive species by naturally sucked air in the Ar plasma jet

In this study, we used an Ar plasma jet to enhance reactive oxygen and nitrogen species (RONS). Atmospheric air was mixed directly with the working gas through the hole of the quartz tube in the discharge region. The electrical, optical, and chemical characteristics of air-mixed Ar plasma via a hole and pure Ar plasma without a hole were compared and analyzed. The hydroxyl (OH) radicals, singlet oxygen (O), and N-2 second positive system (SPS) produced in the gas phase were significantly higher in the air-mixed Ar plasma than that in the pure Ar plasma. In addition, the generation of OH radicals was higher in the gas and liquid phases. Furthermore, the concentrations of nitrogen dioxide (NO2) in air, hydrogen peroxide (H2O2), and nitrite (NO2-) the in liquid phase were measured and were found to be higher in the air-mixed Ar plasma than that in pure Ar plasma. The naturally sucked atmospheric air through the drilled hole could be utilized to enhance the RONS by keeping similar power consumption with pure Ar plasma in the gas and liquid phases at a low cost compared to the discharge conditions of other noble gases. This study will be beneficial in the commercialization of non-thermal plasma jets which could be relevant in biomedical and other non-thermal plasma-related applications.