On the quantification of the dissolved hydroxyl radicals in the plasma-liquid system using the molecular probe method

Yupengxue Ma; Xinning Gong; Bangbang He; Xiaofei Li; Dianyu Cao; Junshuai Li; Qing Xiong; Qiang Chen; Bing Hui Chen; Qing Huo Liu

doi:10.1088/1361-6463/aab379

arXiv · 1709.02801

On the quantification of the dissolved hydroxyl radicals in the plasma-liquid system using the molecular probe method

Yupengxue Ma·Xinning Gong·Bangbang He·Xiaofei Li·Dianyu Cao·Junshuai Li·Qing Xiong·Qiang Chen·Bing Hui Chen·Qing Huo Liu

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Abstract

Hydroxyl (OH) radical is the most important reactive species produced by the plasma-liquid interactions, and the OH in the liquid phase (dissolved OH radical, OHdis) takes effect in many plasma-based applications due to its high reactivity. Therefore, the quantification of the OHdis in the plasma-liquid system is of great importance, and a molecular probe method usually used for the OHdis detection might be applied. Herein we investigate the validity of using the molecular probe method to estimate the [OHdis] in the plasma-liquid system. Dimethyl sulfoxide is used as the molecular probe to estimate the [OHdis] in an air plasma-liquid system, and the partial OHdis is related to the formed formaldehyde (HCHO) which is the OHdis-induced derivative. The analysis indicates that the true concentration of the OHdis should be estimated from the sum of three terms: the formed HCHO, the existing OH scavengers, and the OHdis generated H2O2. The results show that the measured [HCHO] needs to be corrected since the HCHO destruction is not negligible in the plasma-liquid system. We conclude from the results and the analysis that the molecular probe method generally underestimates the [OHdis] in the plasma-liquid system. If one wants to obtain the true concentration of the OHdis in the plasma-liquid system, one needs to know the destruction behavior of the OHdis-induced derivatives, the information of the OH scavengers (such as hydrated electron, atomic hydrogen besides the molecular probe), and also the knowledge of the OHdis generated H2O2.

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BibTeX RIS

Yupengxue Ma, Xinning Gong, Bangbang He, Xiaofei Li, Dianyu Cao, Junshuai Li, Qing Xiong, Qiang Chen, Bing Hui Chen, Qing Huo Liu. 2017-09-27. On the quantification of the dissolved hydroxyl radicals in the plasma-liquid system using the molecular probe method. https://doi.org/10.1088/1361-6463%2Faab379

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