IR and NMR study of nanoparticle-support interactions in a Fe2O3-SiO2 nanocomposite prepared by a sol-gel method

The interaction of iron oxide with the silica matrix in a Fe2O3-SiO2 nanocomposite prepared by a sol-gel method has been investigated using Near-, Mid-, and Far-IR, and 29Si MAS-, and 1H NMR techniques. Samples of nanocomposites and of pure silica obtained by the same preparation procedure and subjected to the same thermal treatments have been examined. Spectroscopic data indicate that the Fe2O3 nanoparticles interact with the silica or silanol groups at the surface of the cavities in which they form. This result allowed us to propose a model for the nanoparticle/silica interface.