(Poster session) Environment & Recycling Group

[2P0607-17-03] 3-C [Student presentation:Doctoral course] Roles of Fe (Ⅲ) as impurities in montmorillonite/ TiO₂ photocatalyst composite

○Li Zhang¹, Chitiphon Chuaicham¹, Keiko Sasaki¹ (1. The University of Kyushu)

Keywords:titanium dioxide, ferric, montmorillonite, photocatalyst, phenol

Fe(Ⅲ)-doped montmorillonite/ TiO₂ composites (Fe-Mt/ TiO₂) and montmorillonite/ Fe(Ⅲ)-doped TiO₂ (Mt/ Fe-TiO₂) with the same stoichiometry but the different locations of Fe(Ⅲ) ions were synthesized and compared for photocatalytic activity. The Fe-Mt/ TiO₂ showed greater photocatalytic activity in the degradation of phenol than the Mt/ Fe-TiO₂. Heterojunction between the Fe(Ⅲ)-doped Mt and TiO₂ was formed since new electron-trap states were expected to generate in Mt by doping Fe(Ⅲ). The electron at the Fermi level on Fe(III)-doped Mt can be combined with the hole on the valance band of TiO₂ (anatase and rutile) leads to efficient separation of electron and hole and reduce and/or avoid the recombination of the electron-hole pairs to improve the photocatalytic property activity of the composite. The better optical property of Fe-Mt/ TiO₂ than Mt/ Fe-TiO₂ was characterized by photoluminescence, diffuse reflectance spectroscopy, photocurrent, and impedance measurements. The higher photocatalytic degradation efficiency of phenol by Fe-Mt/ TiO₂ was consistent with the characterization results.