title: Alkaline-resistant titanium dioxide thin film displaying visible-light-induced superhydrophilicity initiated by interfacial electron transfer.
abstract: We synthesized a three-layer-type photocatalytic structure (TiO2/Cu(II)SiO2/SiO2), consisting of TiO2 on Cu(II)-grafted SiO2, which was deposited on a SiO2-coated glass substrate, and investigated its visible-light absorption and hydrophilic properties. Water contact angle measurements revealed visible-light-induced superhydrophilicity at the film surface that was initiated by interfacial electron transfer (IFET) at the interface of TiO2 and Cu(II)SiO2. Monitoring the oxidation state of Pb(2+) ions confirmed that the IFET-initiated holes diffused to the TiO2 surface, where they likely contributed to the hydrophilic conversion. We also demonstrated that layer-structured TiO2/Cu(II)SiO2/SiO2 was stable under alkaline conditions. Thus, we successfully synthesized alkaline-resistant TiO2 that displays visible-light-induced superhydrophilicity.
authors.affiliation: Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu, Yamanashi, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Taguchi
authors.forename: Lei
authors.initials: L
authors.lastname: Ni
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Irie
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D004579:Electron Transport; D057927:Hydrophobic and Hydrophilic Interactions; D008027:Light; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D000468:Alkalies; D014867:Water; C009495:titanium dioxide; D012822:Silicon Dioxide; D003300:Copper; D014025:Titanium