Antimicrobial Mechanism Based on H2O2 Generation at Oxygen Vacancies in ZnO Crystals

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• 作者：Xiaoling Xu ; Dan Chen ; Zhigang Yi ; Man Jiang ; Li Wang ; Zuowan Zhou ; Ximei Fan ; Yong Wang ; David Hui
• 刊名：Langmuir
• 出版年：2013
• 出版时间：May 7, 2013
• 年：2013
• 卷：29
• 期：18
• 页码：5573-5580
• 全文大小：446K
• 年卷期：v.29,no.18(May 7, 2013)
• ISSN：1520-5827

文摘

The production of H₂O₂ has been taken for a crucial reason for antimicrobial activity of ZnO without light irradiation. However, how the H₂O₂ generates in ZnO suspension is not clear. In the present work, the comparatively detections on three kinds of ZnO, tetrapod-like ZnO whiskers (t-ZnO), nanosized ZnO particles (n-ZnO), and microsized ZnO particles (m-ZnO), showed that the antimicrobial activity of ZnO was correlated with its production of H₂O₂. Oxygen vacancy (V_O) in the surface layer of ZnO crystals determined by XPS indicated that it was quite probably involved in the production of H₂O₂. To validate the role of V_O, the concentration of V_O in t-ZnO was adjusted by heat-treatment under the atmospheres of H₂, vacuum, and O₂, respectively, and the H₂O₂ production and antimicrobial effect were detected. Consistently, the t-ZnO treated in H₂, which possessed the most V_O in its crystal, produced the most H₂O₂ and displayed the best antimicrobial activity. These results provide the basis for developing a more detailed mechanism for H₂O₂ generation catalyzed by ZnO and for taking greater advantage of this type of antimicrobial agent.