Synthesis of Fe2O3 species embedded in a silica xerogel matrix:: A comparative study

In this work we report composites of gamma-Fe2O3/SiO2 and alpha-Fe2O3/SiO2 starting from three different iron precursors: iron nitrate, iron chloride and nanometric Fe particles prepared by aqueous chemical reduction. The composite samples were prepared by the sol-gel method and were ground in order to produce powders, heat treated at different temperatures under atmospheric conditions. The powder samples were characterized by X-Ray diffraction, IR absorption, and UV-visible spectroscopy. A specific composite can be produced depending on the temperature used for reaction.