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论文类型：期刊论文

发表时间：2012-04-03

发表刊物：ENVIRONMENTAL SCIENCE & TECHNOLOGY

收录刊物：SCIE、EI、PubMed、PKU、ISTIC、Scopus

卷号：46

期号：7

页面范围：4042-4050

ISSN号：0013-936X

摘要：A ternary Ag/AgBr/TiO2 nanotube array electrode with enhanced visible-light activity was synthesized by a two-step approach including electrochemical process of anodization and an in situ photoassisted deposition strategy. The dramatically enhanced photoelectrocatalytic activity of the composite electrode was evaluated via the inactivation of Escherichia coli under visible light irradiation (lambda>420 nm), whose performance of complete sterilization was much superior to other reference photocatalysts. PL, ESR, and radicals trapping studies revealed hydroxyl radicals were involved as the main active oxygen species in the photoelectrocatalytic reaction. The process of the damage of the cell wall and the cell membrane was directly observed by ESEM, TEM, and FTIR, as well as further confirmed by determination of potassium ion leakage from the killed bacteria. The present results pointed to oxidative attack from the exterior to the interior of the Escherichia coli by OH center dot, O-2(center dot-), holes and Br-0, causing the cell to die as the primary mechanism of photoelectrocatalytic inactivation.