“…In fact, optical gap values reported in Table 3 are compatible with those of pure component oxides, as well as with the formation of a mixed TiO 2 -MoO 3 phase: E g values of 3.0, 3.2 and 3.35 eV are reported for rutile, anatase and amorphous TiO 2 phase, respectively [12,17,20,21,[52][53][54][55][56], whilst for MoO 3 band gaps equal to 2.9 (␣ phase), 3.1 ( phase) and 3.3 (a-MoO 3 ) eV can be assigned [12,24,[57][58][59]. Similarity in the gap values of the two oxides arises from almost coincident electronegativities of both metal cations [12,60].…”