title: Fabrication of TiO2-Bi2WO6 Binanosheet for Enhanced Solar Photocatalytic Disinfection of E. coli: Insights on the Mechanism.
abstract: TiO2-Bi2WO6 binanosheet (TBWO), synthesized by a facile two-step hydrothermal method, was used as an effective visible-light-driven photocatalyst for the inactivation of E. coli and was characterized by TEM, SEM, XRD, FTIR, XPS, and BET. A series of TBWOs with different doping ratios of TiO2 loading from 10 to 55 wt % were synthesized. Among all of the TBWOs, 40% TBWO exhibited the best bacteria disinfection efficiency, and the quantity of viable bacteria could reach 10° with 40% TBWO (100 μg/mL) after being illuminated for 4 h. Furthermore, the confocal fluorescent-based cell live/dead test and the SEM technology were applied to verify the photocatalytically lethal effect toward E. coli and the rupture of bacterial membranes. The leak of bacterial contents, including the bacterial genome represented by relevant 16srDNA, and total protein were detected by PCR and bicinchoninic acid assay. In this work, the antibacterial mechanism was studied by employing photoelectrochemical techniques, electron spin resonance (ESR), and scavengers of different reactive species, revealing the pivotal roles of electron hole (h(+)) and electron (e(-)) in the photocatalytic process. In addition, the •O2(-) and •OH radicals were also detected in the TBWOs system by ESR. It was found that the adsorption of visible light and separation of photogenerated carriers within TiO2 have been largely promoted after being coupled with Bi2WO6, which should be responsible for the improved bactericidal effect.
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Jia
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Sihui
authors.initials: S
authors.lastname: Zhan
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Shuanglong
authors.initials: S
authors.lastname: Ma
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Qixing
authors.initials: Q
authors.lastname: Zhou
mesh_terms: D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli / Q000254:growth & development* / Q000648:ultrastructure; D049329:Nanostructures / Q000737:chemistry*; D055668:Photochemical Processes; D012993:Solar Energy; D014025:Titanium / Q000737:chemistry*
chemical_list: C009495:titanium dioxide; D014025:Titanium
keywords: Bi2WO6; TiO2; binanosheet; leakage of cell contents; photocatalytic disinfection