Recent advances towards aqueous hydrogen peroxide formation in a direct current plasma–liquid system

Plasma-activated water (PAW) has been utilised in various application fields, and a deep understanding on the plasma chemistry is the foundation of application-orientated optimisation. In this paper, a global model is built to study the chemical properties of PAW produced by a dielectric barrier discharge that is powered by nanosecond voltage pulses. The applied voltage is firstly repeated with 10 kHz frequency for 100 s, and then shut down for 200 s afterglow, providing a long-term evolution regarding the production and consumption of some typical reactive oxygen/nitrogen species (RONS) in PAW. The calculated results agree principally with experimental measurements from literature. During the pulsed discharge, the water gradually acidises, and the long-lived species accumulate; while in the afterglow, most of the aqueous RONS decay rapidly, except for O 3aq , NO − 3aq , H 2 O 2aq and N 2 O aq , which might be the main sources to sustain long-term effects. Furthermore, the effects of applied voltage and gap distance on RONS are investigated. Correlation analyses from Pearson correlation coefficient indicate that gaseous RONS are more sensitive to the gap distance, while the aqueous ones are more sensitive to the voltage amplitude, suggesting the possibility to independently regulating the gaseous and aqueous chemistry.

“…Hydrogen peroxide, another important reactive species in plasma‐liquid system [45], is mainly populated from OH via three pathways:

\mathrm{O}\mathrm{H}+\mathrm{O}\mathrm{H}+\mathrm{M}\to {\mathrm{H}}_{2}{\mathrm{O}}_{2}+\mathrm{M}

{\text{OH}+\text{HO}}_{2}{\text{NO}}_{2}\to {\mathrm{H}}_{2}{\mathrm{O}}_{2}+{\text{NO}}_{3}

\left\{\begin{array}{c}{\text{OH}+\mathrm{O}}_{3}\to {\text{HO}}_{2}+{\mathrm{O}}_{2}\\ {\text{HO}}_{2}+{\text{HO}}_{2}+\mathrm{M}\to {\mathrm{H}}_{2}{\mathrm{O}}_{2}+{\mathrm{O}}_{2}+\mathrm{M}\end{array}\right.

…”

Section: Resultsmentioning

confidence: 99%

“…Hydrogen peroxide, another important reactive species in plasma-liquid system [45], is mainly populated from OH via three pathways:…”

Section: Pulsed Dischargementioning

confidence: 99%

Global model of plasma‐activated water over long time scale: Pulsed discharge and afterglow

Ning

Shang

et al. 2022

“…CAP was initially intended for cancer treatment by directly irradiating on cancer cells or tumours by using proper plasma devices [19,20]. As researches going in depth, plasma-activated liquid (PAL), as a promising plasma medical tool, has attracted more and more attention due to its unique advantages over the cold plasma's contact treatment [21][22][23][24]. On the one hand, PAL could easily be applied to the areas that cannot be irradiated by direct plasma, for example, small tumours hidden deeply inside the body.…”

Section: Introductionmentioning

confidence: 99%

“…The hydroxyl radical (OH) is a highly reactive species renowned for its strong oxidising properties [29], it plays a pivotal role in various applications within plasma medicine. It is also one of the components that are necessary for the formation of H 2 O 2 , which is considered to be an important agent for chemical reactions of plasma in and in contact with liquids [21,30,31]. Several groups have reported a number of measurements of OH density in CAP jet in the last few decades, by using laser-induced fluorescence (LIF) for the most of cases [29,32,33].…”

Section: Introductionmentioning

confidence: 99%

Studies on plasma‐activated perilla seed oil: Diagnosis, optimisation, and validation of reactive species

Wang

et al. 2023

Recently, the applications of cold atmospheric plasma (CAP) in liquid treatment have attracted increasing attention owing to its excellent medical efficacy. It has been proved that CAP can effectively enhance the biological activity of vegetable oils due to the generation of reactive species. Optimising the reactor parameter is an important approach to regulate reactive species in plasma‐activated oil to obtain better biological effects. In this study, a self‐made jet array driven by a pulsed power supply was used to generate large‐area plasma to irradiate perilla seed oil (PSO), with the formation of plasma‐activated perilla seed oil (PAPSO). By means of laser‐induced fluorescence and chemical titration, the relative density of hydroxyl radical radical in plasma jet, as well as the activity of PAPSO were measured under different discharge parameters, and realised the control of the activity of PAPSO. In vitro experiments showed that PAPSO significantly enhanced its ability to inhibit cancer cells proliferation and induce apoptosis after plasma treatment, which provides a reference for cancer treatment. This study is helpful to further understand the influence of plasma dose effect on the activity of media and provide guidance for related plasma medical applications.

“…Plasma-activated liquid has attracted lots of attentions in the past 2 decades because of several emerging applications such as plasma disinfection, plasma agriculture, plasma waste water treatment, plasma material modification and plasma medicine [1][2][3][4][5]. In the past, most of the researchers were focussing on the plasma-activated water (PAW) [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Plasma‐activated ethanol solution and it's decontamination effect

Liu

Zhang

et al. 2022

Ethanol solution as a disinfectant has been widely used in various fields. However, it has a significant bactericidal capability only when the volume fraction of ethanol is around 70%–75%. For such high concentration of ethanol solution, it has an irritating smell. When it is used for applications such as wound disinfection, it causes a stinging sensation. Low concentrations of ethanol solution are less irritating, but it is also less effective at killing bacteria. In this study, an idea for producing a green, efficient and less irritating disinfectant is proposed. It is based on a plasma‐activated low‐concentration ethanol solution (PAES). It is found that the plasma‐activated 10% volume fraction of ethanol solution can kill more than seven orders of magnitude of Escherichia coli, while the untreated 10% volume fraction of ethanol solution has no bactericidal effect. Besides, the PAES's activity remains unchanged after being stored at for three days. Further investigation shows that new compositions including peracetic acid, peroxynitrite, hydrogen peroxide and acetic acid are detected in the PAES, which together are playing the main role of the excellent and prolonged bactericidal effect.