title: Visible-light photocatalytic inactivation of Escherichia coli by K4Nb6O17 and Ag/Cu modified K4Nb6O17.
abstract: Ag/Cu modified K(4)Nb(6)O(17) thin film, a novel type of photocatalyst for photocatalytic inactivation of Escherichia coli under visible light irradiation was developed. The effects of loading method of Cu species on the characteristics of Ag-Cu nanocomposites and photocatalytic antibacterial activity were studied. Samples were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectroscopy (UV-Vis). Irrespective of the preparation method, loading Ag, Cu and Ag-Cu composite as cocatalyst led to an increase in antibacterial activity as compared to bare K(4)Nb(6)O(17). In comparison with conventional impregnation method, well dispersed Ag-Cu nanocomposites were obtained on the K(4)Nb(6)O(17) surface by a sodium borohydride reduction method in the presence PVP. In this case, markedly improvement of photocatalytic activity was observed. The significant enhancement was ascribed to the high efficiency of electron hole pair separation related to the Ag-Cu nanocomposite on K(4)Nb(6)O(17) surface and the synergistic effects of coexisting Ag and Cu ions on antibacterial activity.
authors.affiliation: Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan. hsinyu@mail.ndhu.edu.tw
authors.forename: Hsin-yu
authors.initials: HY
authors.lastname: Lin
authors.forename: Hong-mou
authors.initials: HM
authors.lastname: Lin
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects*; D008027:Light; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009556:Niobium / Q000737:chemistry*; D055668:Photochemical Processes; D056951:Photoelectron Spectroscopy; D033362:Powder Diffraction; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009556:Niobium; D012834:Silver; D003300:Copper