Degradation of isobutanol diluted in water over visible light sensitive vanadium doped TiO2 photocatalyst

Vanadium doped and non-doped TiO2 photocatalysts (V/TiO2 and pure TiO2) were prepared by sol-gel and hydrothermal synthesis method in the presence and absence of NH4F. V/TiO2 exhibited the long-tailed absorption in the visible light region above 380 nm, however, pure TiO2 only show the absorption in the UV light region. Degradation of isobutanol diluted in water proceeded efficiently on V/TiO2 even under visible light (λ > 430 nm), which corresponded to the light absorption of prepared samples. Moreover, it was found that the hydrothermally synthesized V/TiO2 in the presence of NH4F show higher photocatalytic activities than those on V/TiO2 prepared by the sol-gel and hydrothermal treatment in the absence of NH4F, which was attributed to the high crystallinity of anatase phase and hydrophobic surface of V/TiO2 prepared in the presence of NH4F.