Iron oxide/titania photocatalysts derived from TiO2·nH2O coated ferric hydr(oxide) precursors: Characterizations and visible light photocatalytic activity

The synthesis of visible light active Fe2O3/TiO2 photocatalysts, derived from TiO2·nH2O coated ferric hydr(oxide) precursors prepared by a new in-situ (one-step) and conventional ex-situ (two steps) methods and their characterizations by TG–DTA, FT-IR, UV–vis-DRS and TEM were described. TEM images of precursors revealed the formation of uniform TiO2·nH2O coating over ferric hydr(oxide) at least in the case of in-situ method. On calcination at 450 °C, these precursors yielded mainly Fe2O3/TiO2 nanocomposites which showed better visible light activity than degussa P25 towards degradation of rhodamine B. The higher activity of Fe2O3/TiO2 catalyst than degussa P25 was complemented by substantial decrease in their band gap energies (2.22–2.37 eV) from pure titania (3.09 eV). The in-situ method may be further exploited for optimization of iron oxide/TiO2 ratio to obtain better photocatalytic activity under visible/sun lights.