In Situ Photoluminescence of TiO2 as a Probe of Photocatalytic Reactions

Article abstract of DOI:10.1021/j100358a008

The addition of unsaturated hydrocarbons such as 1-C4H8 and <*> onto the TiO2 catalyst causes an increase of the intensity of the photoluminescence (PL) of the catalyst as a radiative surface process from photoformed electrons and holes.The extent of the PL enhancement strongly depends on the ionization potential of the added compounds, i.e., the lower the ionization potential of the added compound, the larger the PL intensity.A parallel relationship between the enhancement of the PL of the TiO2 by the addition of unsaturated hydrocarbons and the rate of photocatalytic hydrogenation of these compounds with H2O on the TiO2 catalyst suggests that these surface processes are closely associated, with both being crucially dependent on the binding of the added molecules to the TiO2 surface.