Abstract
Thin TiO2 films on quartz substrates were prepared by spin coating of undoped
and metal-ion-doped Sol Gel precursors. These films were characterised by
Scanning Electron Microscopy, Laser Raman Microspectroscopy, Xray Diffraction
and UV Vis Transmission. The photocatalytic performances of the films were
assessed by the photo-degradation of methylene-blue in aqueous solution under
UV irradiation. Films exhibited a high degree of orientation and a thermal
stabilization of the anatase phase as a result of substrate effects. In the
absence of dopants, the rutile phase formed as parallel bands in the anatase
which broadened as the transformation progressed. TiO2 films doped or co-doped
with transition metals exhibited the formation of rutile in segregated clusters
at temperatures under 800C as a result of increased levels of oxygen vacancies.
Photocatalytic activity of the films synthesised in this work was low as likely
a result of poor TiO2 surface contact with dye molecules in the solution. The
presence of transition metal dopants appears detrimental to photocatalytic
activity while the performance of mixed phase films was not observed to differ
significantly from single phase material.
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