HETEROGENEOUS PHOTOCATALYTIC REACTIONS OF NITRITE OXIDATION AND CR(VI) REDUCTION ON IRON-DOPED TITANIA PREPARED BY THE WET IMPREGNATION METHOD

Samples of iron-doped titania prepared by the wet impregnation method from TiO2 (Degussa P-25) and two different precursors, Fe(NO3)(3) . 9H (2)O and Fe(III) acetylacetonate, were tested as photocatalysts in two reactions: nitrite oxidation and Cr(VI) reduction at pH 6.5. Whereas samples prepared from Fe(NO3)(3) . 9H(2)O containing low amounts of ir on (less than 2 wt.%) were more efficient for nitrite oxidation than p ure TiO2, specimens obtained from Fe(III) acetylacetonate were less ac tive. in the case of Cr(VI) reduction, all doped samples were less act ive than TiO2 with no sensibly differential activity. Different mechan istic pathways and structural and surface properties of the samples ar e invoked to explain the observed behavior. (C) 1998 Elsevier Science B.V.