Efficient Decomposition of Organic Pollutants Over In2O3/TiO2 Nanocomposite Photocatalyst Under Visible Light Irradiation

The heterojunction structures of In2O3/TiO2, exhibiting visible light photocatalytic efficiency, has been synthesized by utilizing maleic acid as an organic linker to combine In2O3 and Degussa P25 (TiO2) nanoparticles. The prepared nanocomposite has been characterized by FESEM, TEM, XRD and UV–Visible reflectance spectra. The photocatalytic efficiency of the composite photocatalyst has been investigated based on the decomposition of 2-propanol (IP) in gas phase and 1,4-dichlorobenzene (DCB) in aqueous phase under visible light (λ ≥ 420 nm) irradiation. The results reveal that the In2O3/TiO2 composite photocatalyst with 7 wt% In2O3 demonstrated 6.3 times of efficiency in evolving CO2 from gaseous IP and 8.7 times of efficiency in removing aqueous DCB in compare with Degussa P25. In this In2O3/TiO2 composite system, TiO2 seems to be the principal photocatalyst whereas the function of In2O3 is to sensitize TiO2 by absorbing visible light (λ ≥ 420 nm). The extraordinary high photocatalytic efficiency of this composite In2O3/TiO2 under visible light has been explained on the basis of relative energy band positions of the component semiconductors.