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Chemical and mechanochemical route to transition metal oxides with controlled morphology

Chemical and mechanochemical preparation offers wide possibilities in preparation of transition metal oxides. Our research group has wide experience in sol-gel, hydrothermal and mechanochemical synthesis of ZrO2, ZrTiO4 and various titanates. All three methods start from pure substances (alkoxides and salts in case of the chemical route, oxides in case of the mechanochemical) and enable full control of the chemical composition of the final product. They result in amorphous or nanosized powders, nanotubes (in case of hydrothermal synthesis) or films (in case of sol-gel), that can subsequently be calcined in order to obtain desired crystalline structure. Size of initial amorphous particles, shape and size of nanotubes, porosity of produced compact bodies or films and the crystalline structure are influenced by conditions of preparation and thermal treatment. We have successfully prepared porous ZrTiO4 and ZrO2 ceramic bodies, titanate nanotubes, as well as stable ZrO2 coatings on steel. The crystal structure and morphology were studied by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy and energy dispersive X-ray spectroscopy. Phase transformations were also followed by thermal analysis methods (combined differential thermal analysis and thermogravimetric analysis, thermodillatometry) while surface area was determined by BET analysis.

hydrothermal synthesis; mechanochemical synthesis; sol-gel process; transition metal oxides

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