title: Large-scale synthesis of TiO2 nanorods via nonhydrolytic sol-gel ester elimination reaction and their application to photocatalytic inactivation of E. coli.
abstract: A simple method of synthesizing a large quantity of TiO(2) nanorods was developed. A nonhydrolytic sol-gel reaction between titanium(IV) isopropoxide and oleic acid at 270 degrees C generated 3.4 nm (diameter) x 38 nm (length) sized TiO(2) nanocrystals. The transmission electron microscopic image showed that the particles have a uniform diameter distribution. X-ray diffraction and selected-area electron diffraction patterns combined with high-resolution transmission electron microscopic image showed that the TiO(2) nanorods are highly crystalline anatase crystal structure grown along the [001] direction. The diameters of the TiO(2) nanorods were controlled by adding 1-hexadecylamine to the reaction mixture as a cosurfactant. TiO(2) nanorods with average sizes of 2.7 nm x 28 nm, 2.2 nm x 32 nm, and 2.0 nm x 39 nm were obtained using 1, 5, and 10 mmol of 1-hexadecylamine, respectively. The optical absorption spectrum of the TiO(2) nanorods exhibited that the band gap of the nanorods was 3.33 eV at room temperature, which is 130 meV larger than that of bulk anatase (3.2 eV), demonstrating the quantum confinement effect. Oleic acid coordinated on the nanorod surface was removed by the reduction of the carboxyl group of oleic acid, and the Brunauer-Emmett-Teller surface area of the resulting naked TiO(2) nanorods was 198 m(2)/g. The naked TiO(2) nanorods exhibited higher photocatalytic activity than the P-25 photocatalyst for the photocatalytic inactivation of E. coli.
authors.affiliation: National Creative Research Initiative Center for Oxide Nanocrystalline Materials and School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Joo
authors.forename: Soon Gu
authors.initials: SG
authors.lastname: Kwon
authors.forename: Taekyung
authors.initials: T
authors.lastname: Yu
authors.forename: Min
authors.initials: M
authors.lastname: Cho
authors.forename: Jinwoo
authors.initials: J
authors.lastname: Lee
authors.forename: Jeyong
authors.initials: J
authors.lastname: Yoon
authors.forename: Taeghwan
authors.initials: T
authors.lastname: Hyeon
mesh_terms: D002384:Catalysis; D004926:Escherichia coli; D004952:Esters / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D044367:Phase Transition; D010777:Photochemistry; D013053:Spectrophotometry; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004952:Esters; D014867:Water; C009495:titanium dioxide; D014025:Titanium