Efficient Decomposition of Organic Pollutants Over In sub(2)O sub(3)/TiO sub(2) Nanocomposite Photocatalyst Under Visible Light Irradiation

The heterojunction structures of In sub(2)O sub(3)/TiO sub(2), exhibiting visible light photocatalytic efficiency, has been synthesized by utilizing maleic acid as an organic linker to combine In sub(2)O sub(3) and Degussa P25 (TiO sub(2)) 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 ( lambda greater than or equal to 420 nm) irradiation. The results reveal that the In sub(2)O sub(3)/TiO sub(2) composite photocatalyst with 7 wt% In sub(2)O sub(3) demonstrated 6.3 times of efficiency in evolving CO sub(2) from gaseous IP and 8.7 times of efficiency in removing aqueous DCB in compare with Degussa P25. In this In sub(2)O sub(3)/TiO sub(2) composite system, TiO sub(2) seems to be the principal photocatalyst whereas the function of In sub(2)O sub(3) is to sensitize TiO sub(2) by absorbing visible light ( lambda greater than or equal to 420 nm). The extraordinary high photocatalytic efficiency of this composite In sub(2)O sub(3)/TiO sub(2) under visible light has been explained on the basis of relative energy band positions of the component semiconductors.