Preparation and properties of metal oxides prepared from organically modified precursors by sol-gel processing

15.03.2011 - 14.03.2015
Research funding project
Metal oxides prepared by sol-gel processing from molecular precursors, such as hydrolyzable metal salts or metal alkoxides, are initially obtained in amorphous or nanocrystalline form, but can be converted to crystalline materials by high-temperature treatment. An advantage of sol-gel processing relevant to this project is the fact that metal oxides (films or bulk) of any composition can be prepared, including mixed-metal, doped or non-stoichiometric metal oxides. The employed metal alkoxides are often derivatized by organic ligands for various chemical or technological reasons. The PI has previously investigated the chemistry of organically modified metal alkoxide precursors with a variety of bidentate O- and N-donor ligands. The question to be addressed in the SFB is how the organic co-ligands of the precursors influence the morphology and texture of the obtained oxides. The studies will be performed on selected oxides relevant to the SFB, e.g. by sol-gel processing of organically modified Zr or Ce alkoxides for the synthesis of ZrO2 or CeO2. Our hypothesis is that the kind and proportion of organic co-ligands influence the structure, size and surface properties of the initially formed particles (which eventually make up the gel network) and thus influence the microstructure (grain size, grain boundaries, etc.) and properties of the crystalline oxides once the organic groups are removed by calcination. A related aspect is the question whether the number and kind of defects in the obtained oxides is influenced by kind of organic groups in the precursors, and whether thermal degradation of the organic groups gives rise to impurities that may positively or negatively influence the physical properties of the oxide materials. In previous work of the group, a general method for the creation of monodisperse metal particles inside silica has been developed by thermal decomposition of metal complexes tethered to the sol-gel network. This work will be extended to metal nanoparticles in metal oxides, especially to produce tailor-made metal-doped oxides relevant to other sub-projects of the SFB (for example, Ni or Pt nanoparticles in a zirconia or ceria matrix). A general question to be addressed in cooperation with other groups of the SFB is how the metal particles interact with the gel matrix.

People

Project leader

Institute

Grant funds

  • FWF - Österr. Wissenschaftsfonds (National) Austrian Science Fund (FWF)

Research focus

  • Non-metallic Materials: 80%
  • Computational Materials Science: 20%

Keywords

GermanEnglish
Nanokompositenanocomposites
Sol-Gel Prozesssol-gel processing
Metalloxidemetal oxides

Publications