SnO-nanocluster modified anatase TiO2 photocatalyst: exploiting the Sn(II) lone pair for a new photocatalyst material with visible light absorption and charge carrier separation
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Accepted Version
Date
2013-04-26
Authors
Iwaszuk, Anna
Nolan, Michael
Journal Title
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Volume Title
Publisher
The Royal Society of Chemistry
Published Version
Abstract
Modifying TiO2 to design new photocatalysts with visible light absorption and reduced charge carrier recombination for photocatalytic depollution or water splitting is a very active field. A promising approach is to deposit small nanoclusters of a metal oxide on a semiconducting oxide such as TiO2 or ZnGa2O4. In this paper we present a first principles density functional theory (DFT) investigation of a novel concept in photocatalyst materials design: Sn(II)O nanoclusters supported on TiO2 anatase (001) and demonstrate that the presence of the Sn(II)-O lone pair in the nanoclusters gives a new approach to engineering key properties for photocatalysis. The modification of anatase with Sn(II)O reduces the band gap over unmodified anatase, thus activating the material to visible light. This arises from the upwards shift of the valence band, due to the presence of the Sn 5s-O 2p lone pair in the nanocluster. Enhanced charge separation, which is key for photocatalytic efficiency, arises from the separation of electrons and holes onto the anatase surface and the Sn(II)O nanocluster. This work realises a new strategy of exploiting the lone pair in elements such as Sn to raise the VB edge of modified TiO2 and enhance charge separation in new photocatalyst materials.
Description
Keywords
Density functional theory (DFT) , Titanium(IV) dioxide , Doped TiO2 , Iron oxide , Electronic structure , Rutile TiO2 , Band-gap , Surface , Irradiation , 1st principles
Citation
Iwaszuk, A. and Nolan, M. (2013) 'SnO-nanocluster modified anatase TiO2 photocatalyst: exploiting the Sn(ii) lone pair for a new photocatalyst material with visible light absorption and charge carrier separation', Journal of Materials Chemistry A, 1(22), pp. 6670-6677. doi: 10.1039/C3TA10647K
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© The Royal Society of Chemistry 2013. This is the Accepted Manuscript version of a published work that appeared in final form in Journal of Materials Chemistry A. To access the final published version of record, see http://pubs.rsc.org/en/content/articlepdf/2013/ta/c3ta10647k