Issue 17, 2011

Electronic basis of visible region activity in high area Sn-doped rutile TiO2 photocatalysts

Abstract

The influence of Sn doping on the anatase-to-rutile phase transition has been investigated in high area powders prepared by a sol–gel route involving alkoxide precursors. Sn doping facilitates conversion of anatase to rutile at lower temperatures than observed for undoped material. At the same time Sn-doping inhibits sintering as gauged by line widths in X-ray diffraction and gas-adsorption surface area measurements. These observations are linked to the finding of pronounced segregation of Sn to the surface of rutile TiO2 observed in X-ray photoemission spectra. Sn-doped TiO2 is found to exhibit enhanced visible region photocatalytic activity as compared with undoped material in dye degradation experiments. This is attributed to narrowing of the bulk bandgap at low doping levels coupled with the introduction of surface states associated with segregated Sn ions in the divalent state. The Sn(II) surface states lie above the top of the main valence band and can therefore act as trapping sites for holes produced under photoexcitation.

Graphical abstract: Electronic basis of visible region activity in high area Sn-doped rutile TiO2 photocatalysts

Article information

Article type
Paper
Submitted
23 Nov 2010
Accepted
23 Feb 2011
First published
28 Mar 2011

Phys. Chem. Chem. Phys., 2011,13, 7882-7891

Electronic basis of visible region activity in high area Sn-doped rutile TiO2 photocatalysts

F. E. Oropeza, B. Davies, R. G. Palgrave and R. G. Egdell, Phys. Chem. Chem. Phys., 2011, 13, 7882 DOI: 10.1039/C0CP02639E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements