Photocatalytic activities of various titania (TiO2) based catalytic systems were investigated under
UV, visible and in the dark. It was found that the activity in the dark of TiO2 could be induced when
the metal oxide was used in combination with V2O5 in a form of hybrid metal oxides, TiO2/(TiO2–
V2O5). Next, TiO2/PPy and a series of TiO2/(TiO2–V2O5)/PPy nanocomposites were then prepared via
in situ polymerization of pyrrole with FeCl3 under various reaction times. The results from FTIR,
TGA and SEM–EDX are sufficient to confirm that the various metal oxides/PPy nanocomposites have
been successfully prepared. The presence of polymer resulted in a lower photocatalytic activity of
TiO2. However, for the hybrid metal oxides (TiO2/(TiO2–V2O5), the presence of polymer enhanced photocatalytic
activity of the system under both UV and visible light. The above results were discussed in
relation to the energy storage ability of V2O5 and a capability of the semi-conducting polymer in acting
as a binder for the hybrid metal oxides. Overall, our results show that the hybrid metal oxides/polymer
nanocomposite can degrade methylene blue both under both UV/visible light and in the dark. The catalytic
activities of the hybrid nanocomposite under both UV irradiation, visible light illumination and
in the dark conditions were optimized when TiO2/(TiO2–V2O5)/PPy was prepared via in situ polymerization
for 6 h.