title: Different hollow and spherical TiO2 morphologies have distinct activities for the photocatalytic inactivation of chemical and biological agents.
abstract: The inactivation of Escherichia coli and Qβ phage was examined following their photocatalytic treatment with TiO2 hollows and spheres that had been prepared by electrospray, hydrothermal treatment, and calcination. The crystal structures of the hollows and spheres were assigned to TiO2 anatase, and the surface areas of the hollows and spheres were determined to be 91 and 79 m(2) g(-1), respectively. Interestingly, TiO2 spheres exhibited higher anti-pathogen performance than TiO2 hollows, a difference we ascribe to the prevention of light multi-scattering by microorganisms covering the surfaces of the TiO2 particles. The photocatalytic decomposition of dimethyl sulfoxide (DMSO) in the presence of TiO2 hollows and spheres was examined in order to study the dependence of photocatalytic activity on TiO2 morphology for the size scale of the reactants. TiO2 hollows provided greater photocatalytic decomposition of DMSO than did TiO2 spheres, in contrast to the pattern seen for pathogen inactivation. Fabrication of photocatalysts will need to vary depending on what substance (e.g., organic compound or biological agent) is being targeted for environmental remediation.
authors.affiliation: Research Institute for Science and Technology, Photocatalysis International Research Center, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan. nakata@rs.tus.ac.jp.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Takahito
authors.initials: T
authors.lastname: Shimodo
authors.forename: Sho
authors.initials: S
authors.lastname: Usuki
authors.forename: Kanjiro
authors.initials: K
authors.lastname: Torigoe
authors.forename: Chiaki
authors.initials: C
authors.lastname: Terashima
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Katsumata
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ikekita
authors.forename: Akira
authors.initials: A
authors.lastname: Fujishima
authors.forename: Hideki
authors.initials: H
authors.lastname: Sakai
authors.forename: Kazuya
authors.initials: K
authors.lastname: Nakata
mesh_terms: D017908:Allolevivirus / Q000187:drug effects; D002384:Catalysis; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D008751:Methylene Blue / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D013056:Spectrophotometry, Ultraviolet; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: C009495:titanium dioxide; D014025:Titanium; D008751:Methylene Blue; D004121:Dimethyl Sulfoxide