Peer-Reviewed Journal Details
Mandatory Fields
Nolan, Michael; Iwaszuk, Anna; Tada, Hiroaki
Australian Journal Of Chemistry
Molecular Metal Oxide Cluster-Surface Modified Titanium(IV) Dioxide Photocatalysts
Optional Fields
Bilayer-type photocatalyst Visible-light photocatalysis TiO2 photocatalysis Band-gap Semiconductor Irradiation Transition Particles Anatase Design Adsorption Chemisorption Degradation Density functional theory Ion exchange Iron oxides Loading Metallic compounds Organic conductors Oxide minerals Photocatalysis Photocatalysts Surfaces Tin Tin oxides Titanium
The surface modification of TiO2 with molecular sized metal oxide clusters has recently been shown to be a promising approach for providing TiO2 with visible-light activity and/or improved UV activity. This short review summarizes the effects of the surface modification of TiO2 with the oxides of iron and tin selected from d- and p-blocks, respectively, on the photocatalytic activity. Fe(acac)(3) and [Sn(acac)(2)]Cl-2 chemisorption on the TiO2 surface occurs by ligand-exchange and ion-exchange, respectively. Taking advantage of the strong adsorption, we formed extremely small metal oxide clusters on TiO2 by the chemisorption-calcination cycle (CCC) technique with their loading amount strictly controlled. The iron oxide surface modification of P-25 (anatase/rutile = 4: 1, w/w, Degussa) gives rise to a high level of visible-light activity and a concomitant increase in the UV-light activity for the degradation of model organic pollutants. On the other hand, only the UV-light activity is increased by the tin oxide surface modification of ST-01 (anatase, Ishihara Sangyo). This striking difference can be rationalized on the basis of the material characterization and DFT calculations, which show that FeOx surface modification of rutile leads to visible-light activity, while SnO2-modified anatase enhances only the UV-light activity. We propose the mechanisms behind the FeOx and SnO2 surface modification, where the surface-to-bulk and bulk-to-surface interfacial electron transfer are taken into account in the former and the latter, respectively.
DOI 10.1071/CH11451
Grant Details
Science Foundation Ireland