title: Fabrication of Ag-Decorated CaTiO₃ Nanoparticles and Their Enhanced Photocatalytic Activity for Dye Degradation.
abstract: CaTiO₃nanoparticles of 30-40 nm in size were synthesized via a polyacrylamide gel route. Ag nanoparticles with size of 8-16 nm were deposited onto CaTiO₃particles by a photochemical reduction method to yield CaTiO₃@Ag composites. The photocatalytic activity of prepared samples was evaluated by degrading methyl orange under ultraviolet irradiation. It is demonstrated that Ag-decorated CaTiO₃ particles exhibit an enhanced photocatalytic activity compared to bare CaTiO₃ particles. After 60 min of photocatalysis, the degradation percentage of MO increases from 54% for bare CaTiO₃particles to 72% for CaTiO₃@Ag composites. This can be explained by the fact that photogenerated electrons are captured by Ag nanoparticles and photogenerated holes are therefore increasingly available to react with OH⁻/H₂O to generate hydroxyl (·OH) radicals. ·OH radicals were detected by fluorimetry using terephthalic acid as a probe molecule, revealing an enhanced yield on the irradiated CaTiO₃@Ag composites. In addition, it is found that the addition of ethanol, which acts as an ·OH scavenger, leads to a quenching of ·OH radicals and simultaneous decrease in the photocatalytic efficiency. This suggests that ·OH radicals are the dominant active species responsible for the dye degradation.
authors.forename: T
authors.initials: T
authors.lastname: Xian
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.forename: Y S
authors.initials: YS
authors.lastname: Huo
authors.forename: J Y
authors.initials: JY
authors.lastname: Ma
authors.forename: H M
authors.initials: HM
authors.lastname: Zhang
authors.forename: J Y
authors.initials: JY
authors.lastname: Su
authors.forename: W J
authors.initials: WJ
authors.lastname: Feng
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D055668:Photochemical Processes; D012834:Silver / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D001391:Azo Compounds; D017610:Calcium Compounds; D017665:Hydroxyl Radical; D012834:Silver; C100258:methyl orange; D014025:Titanium; C046804:titanium hydroxide