MESOSTRUCTURED TIO2 - LIGAND-STABILIZED SYNTHESIS AND CHARACTERIZATION

The synthesis of mesostructured or even mesoporous metal oxides requir es a certain interaction between the inorganic precursor and the organ ic structure-directing supramolecular template. In order to adapt the reactivity of a titanium alkoxide precursor for the synthesis of mesos tructured TiO2, three different bidentate ligands -1,3-propanediol, 1, 5-pentanediol and 2,4-pentanedione -were used. Due to their stabilizin g properties, different mesostructured titania phases with structure p eriodicities in the order of 31.5 to 34 Angstrom could be synthesized. The resulting organic-inorganic composite structure did not show a su fficiently high degree of condensation between the TiO6 octahedra. X-r ay absorption spectroscopic (XAS) studies revealed slightly larger bon d lengths compared to the corresponding condensed phase anatase. All w ays to remove the template lead to more condensed phases.