Measurement of reactive species in different solutions of bubble discharge with varying O₂/N₂ proportion in Ar: Analysis of reaction pathways

Abstract

The generation of species in gas phase and long-lived species in deionized water and D-mannitol solution of a bubble discharge in dependence on bubbled gas atmosphere with different O 2 /N 2 proportion are studied. Argon is mixed to enhance the discharge. The optical emission spectra and Fouriertransform infrared spectroscopy are used to diagnose gaseous species and exhaust gas components, and study the effects of O 2 /N 2 proportion on the species intensities. The aqueous species and OH radical are measured by chemical probes to reveal the role of OH radical on the formation of long-lived species. The liquid species and exhaust gas are also analyzed varying with O 2 /N 2 proportion to demonstrate the effect of O 2 -based radicals on the formation of long-lived species.

Magnetic field improves ozone production in an atmospheric pressure surface dielectric barrier discharge: understanding the physico-chemical mechanism behind low energy consumption

“…7(a)), where the OES intensity could be an approximate substitute for the transient species relative content. 67 The O was an essential reactant in the three-body collision reaction that generated O 3 (R8) and (R9), and the increased O provided more reactants for the reactions of (R8) and (R9), favouring the generation of more O 3 as shown in Fig. 3(a).…”

“…At lower ε , electron dissociation of N 2 was not yet obvious because the dissociation energy of N 2 was significantly higher than that of O 2 (9.79 eV vs. 5.12 eV). 67,69,70 But under excessive ε , the dissociation of N 2 was not negligible, which generated N and N ( 2 D) through (R5) and (R6). According to the reactions of (R16) and (R17), the N and N ( 2 D) also contributed the O 3 decomposition.…”

The influences of shielding gas and quartz tube on discharge properties and reactive species productions of nanosecond pulsed gas–liquid discharge

“…Under a certain discharge gap, adding extra shielding gas and tube leads to higher solution pH values compared with no shielding case, which suggests that the existence of shielding gas and tube can slow down the solution acidification caused by plasma processing. As well known, the liquid acidification caused by plasma treatments is attributed to the generation of N x O y , such as NO, N 2 O, and NO 2 , which leads to the productions of nitrous and nitric acid [3,17,26]. Compared with the plasma generated in all shielding cases, the interaction between plasma and air ambient in no shielding case causes higher N x O y generation, which results in a lower pH value.…”

“…The aqueous H 2 O 2 concentration is measured by using chemical probe based on titanium sulfate method. The detailed measurement information can be found in our previous works [26]. It should be noted that the decompositions of NO •OH concentration is measured by using chemical probe method based on terephthalic acid (TA) method [18,28].…”

“…The ratios of emission intensity of OH (A-X), H β (486.1 nm), H α (656.4 nm), and He (587 nm) to N 2 (C-B, 337 nm) increase in the order of no shielding < straight tube < conical tube < shielding gas. The excited state of OH (A) (∼4.2 eV) and H (3p) (∼12.1 eV) are mainly generated by the dissociation excitation of H 2 O molecules impacted with high energy electron or excited state He * and N 2 * (R8-R15) [17,26,41]. In general, water molecules derive from water vapor caused by discharge heating effect.…”