title: Bactericidal activity and mechanism of AgI/AgBr/BiOBr(0.75)I(0.25) under visible light irradiation.
abstract: The AgI/AgBr/BiOBr0.75I0.25 nanocomposites were synthesized by a solvothermal process, followed by an in-situ ion exchange reaction. The disinfection activities of the as-synthesized photocatalyst to model cell type, Gram-negative Escherichia coli (E. coli), were investigated under visible light irradiation condition (λ≥400 nm). Results showed that 80 mg/L AgI/AgBr/BiOBr0.75I0.25 could completely inactivate 3×10(7) CFU mL(-1)E. coli cells within 30 min under visible light irradiation. Moreover, the bactericidal mechanisms involved in the photocatalytic disinfection process were systematically investigated. Ag(+) ions released from the nanocomposites negligibly contributed to the bactericidal activity, while active species including h(+), e(-) and ·O2(-) played important roles in the disinfection system. Direct contact of bacterial cells and nanoparticles was found to be the prerequisite for both the generation of ·O2(-) and the disinfection processes. The disruption of cell membrane and emission of cytoplasm directly inactivated E. coli cells. In addition, AgI/AgBr/BiOBr0.75I0.25 exhibited strong antibacterial activity toward E. coli even in four consecutive reused cycles.
authors.affiliation: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
authors.forename: Jialiang
authors.initials: J
authors.lastname: Liang
authors.affiliation: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Deng
authors.affiliation: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
authors.forename: Mian
authors.initials: M
authors.lastname: Li
authors.affiliation: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China. Electronic address: tongmeiping@pku.edu.cn.
authors.forename: Meiping
authors.initials: M
authors.lastname: Tong
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D001729:Bismuth / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects / Q000528:radiation effects; D004203:Disinfection / Q000379:methods; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure; D007454:Iodides / Q000737:chemistry*; D008027:Light; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D056951:Photoelectron Spectroscopy; D011188:Potassium / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry; D018030:Silver Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D001965:Bromides; D007454:Iodides; D017382:Reactive Oxygen Species; D018030:Silver Compounds; C030584:silver iodide; C542279:bismuth oxybromide; C047751:silver bromide; D011188:Potassium; D001729:Bismuth
keywords: Active species; AgI/AgBr/BiOBr(0.75)I(0.25); Direct contact; Inactivation activity; Reusability