Nano-structuring of complex metal oxides for catalytic oxidation

New crystalline solid materials of Mo3VOx having high-dimensional structures were synthesized in a single crystalline form using a hydrothermal method where the essential structural unit in the structure already presents in the preparative solution and the fundamental structure of Mo3VOx is formed as a result of self-organization between negatively charged pentagonal units and VO2+ cations. We also synthesized metal oxides by using organic solids with particular shapes as templates in order to create nano-macrostructures. Three-dimensionally ordered macroporous (3DOM) materials of polycrystalline spinel- and perovskite-type materials were fabricated using a colloidal crystal template method in extremely high yield. In the synthesis of oxide nanotubes, we demonstrate that various oxide nanotubes could be synthesized by the adsorption and hydrolysis of precursors on the surface of carbon nanofiber templates and by the oxidative removal of templates. A variety of oxide nanotubes such as thick, thin, and helical nanotubes reflecting the shapes of carbon nanofibers could be synthesized.