Visible-Light-Driven Photocatalytic Inactivation of E. coli K-12 by Bismuth Vanadate Nanotubes: Bactericidal Performance and Mechanism

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• 作者：Wanjun Wang ; Ying Yu ; Taicheng An ; Guiying Li ; Ho Yin Yip ; Jimmy C. Yu ; Po Keung Wong
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：April 17, 2012
• 年：2012
• 卷：46
• 期：8
• 页码：4599-4606
• 全文大小：374K
• 年卷期：v.46,no.8(April 17, 2012)
• ISSN：1520-5851

文摘

Bismuth vanadate nanotube (BV-NT), synthesized by a template-free solvothermal method, was used as an effective visible-light-driven (VLD) photocatalyst for inactivation of Escherichia coli K-12. The mechanism of photocatalytic bacterial inactivation was investigated by employing multiple scavengers combined with a simple partition system. The VLD photocatalytic bacterial inactivation by BV-NT did not allow any bacterial regrowth. The photogenerated h⁺ and reactive oxidative species derived from h⁺, such as 鈥H_ads, H₂O₂ and 鈥O₂/鈥₂^{鈥?/sup>, were the major reactive species for bacterial inactivation. The inactivation by h+ and 鈥H_ads required close contact between the BV-NT and bacterial cells, and only a limited amount of H₂O₂ could diffuse into the solution to inactivate bacterial cells. The direct oxidation effect of h+ to bacterial cells was confirmed by adopting F鈥?/sup> surface modification and anaerobic experiments. The bacterial cells could trap e鈥?/sup> in order to minimize e鈥?/sup>-h+ recombination, especially under anaerobic condition. Transmission electron microscopic study indicated the destruction process of bacterial cell began from the cell wall to other cellular components. The 鈥H_ads was postulated to be more important than 鈥H_bulk and was not supposed to be released very easily in the BV-NT bacterial inactivation system.}