Photoreactivity of nanostructured semiconducting oxides
Lead Research Organisation:
University of St Andrews
Department Name: Chemistry
Abstract
This research will investigate how the fundamental processes of formation of valence band holes and conduction band electrons when oxide semiconductors are irradiated with UV light depend on the crystal structure, morphology and nanostructure of the semiconductor. Improved understanding of these processes is crucial if oxide semiconductors are to be used more widely as photocatalysts, in photovoltaic cells, and in other devices exploiting their photoelectronic properties. The project will draw upon a collaboration between the group of Zhou, at St Andrews, with particular expertise in synthesis and structural characterisation of materials using electron microscopy, and Howe, at Aberdeen, who has experinece of using EPR and FTIR spectroscopy to follow processes occurring in semiconductors and at their surfaces. Different nanostructured forms of TiO2 will be synthesised, and their photoreactivity investigated by a combination of in-situ EPR and FTIR spectroscopies. We will also examine composite semiconductors, using TiO2-WO3 as a model example, in order to understand why such composite semiconductors may show improved performance under visible light excitation.The project will employ two PhD students, one in St-Andrews and one in Aberdeen, who will learn complementary skills in this rapidly evolving area of materials chemistry.
Organisations
People |
ORCID iD |
Wuzong Zhou (Principal Investigator) |
Publications
Macdonald I
(2010)
In situ EPR studies of electron trapping in a nanocrystalline rutile
in Journal of Photochemistry and Photobiology A: Chemistry
Description | Nanocrystals of rutile, a phase of TiO2, was synthesized. In situ EPR study of electron trapping in this material was performed. Based on experimental results, we proposed that under irradiation there is a dynamic equilibrium established between creation of conduction band electrons, trapping of electrons, and excitation from trap sites back into the conduction band. When irradiation is stopped, conduction band electrons are trapped and remain so in the dark. This fundamental research is presented in a paper. |
Exploitation Route | Some researchers may find the results are interesting in understanding the properties of semiconductors. |
Sectors | Chemicals Energy Environment |
Description | The knowledge of properties of semiconducting TiO2 nanocrystals has been improved. The impact is limited in academic community at moment. |
First Year Of Impact | 2010 |
Sector | Chemicals,Energy,Environment |
Impact Types | Economic |