Enhanced photocatalytic performance for methylene blue degradation of TiO2 by transition metal oxides hybrid MxOy (M = Fe, V, W)

Water contamination along with the environmental issues resulted by industrial wastewaters have caused a trend in applying semiconducting photocatalysts, among which TiO2 composites have been particularly focused on to overcome the drawbacks of titanium(IV) oxide. The experimental results indicated that TiO2 is combined transition metal oxides MxOy (M = Fe, V, W) for higher photocatalytic activity than pure TiO2 for the degradation of methylene blue 20mg/l (MB) under visible light irradiation. The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate due to the formation of MxOy/TiO2. Electron can tranfer easily in the composite with bangap energy  is smaller than pure TiO2. The result is the light absorption of the modified TiO2 showed an apparent extension to visible light region with TiO2-MxOy. The photocatalysis efficiency under visible light irradiation of TiO2-WO3 is higher than TiO2-V2O5, TiO2-Fe2O3 due to the valence potential energy of WO3 is very large, can oxidize water to create OH• to help decompose strongly organic substances.