The direction of photogenerated charge carriers transfer in TiO2–Fe2O3 and TiO2–CuO
Coupled TiO2-based semiconductor systems have attracted much interest because of synergistic effect on photocatalytic activity. Here, we prepared TiO2/Fe2O3 and TiO2/CuO bilayer-type photocatalyst film and carried out the photodeposition of Ag to identify the reduction sites. We found that in TiO2/Fe2O3 (CuO) boundary, deposition occurred preferentially on the side of TiO2. This phenomenon can be explained by semiconductor physics principle, not by the classical theory of the interparticle electron transfer.