  An accurate experimental determination of electronic structure in
semi-conductors nanopowders is a challenging task. We propose here to combine
UPS and UV-Vis spectroscopies in order to get the full description of
electronic bands alignment of powder samples, TiO2 rutile and anatase. For UPS
measurements, two preparation methods, namely dropping method and
electrophoretic deposition, were used to prepare layers of titania powders on a
conducting substrate, ITO or Ag. Both methods lead to comparable results, with
a quantitative description of the energy levels from the valence band.
Combining these results with the UV-Vis spectra of the same powders, enables to
determine the absolute position of the valence band maximum and of the
conduction band minimum. Combined UPS--UV-vis spectroscopy provides a better
insight into the properties of a powdered material which can differ from single
crystal model systems. It can be also used to predict the electronic transfer
in mixed phase systems during, in photocatalytic processes.
