engleski

Nanocrystalline anatase derived from modified alkoxide mesostructured gel

A sol prepared by chelation of titanium n- butoxide with ethyl acetoacetate (1:1) was slowly hydrolyzed, and the obtained gel was thermally treated in order to produce anatase. Samples were investigated by means of FTIR, XRD, DTA/TG, N2 adsorption–desorption isotherms, FESEM and HRTEM. It was determined the modified alkoxide is partially hydrolyzed, leaving small amount of butoxide and ethyl acetoacetate groups attached to titanium. XRD pattern and HRTEM micrograph revealed gel ordering at the mesostructure scale. Observed mesostructure was found to be consisted with inorganic–organic nanoclusters, exhibiting some polydispersity in the size and variations in composition. Thermal decomposition exhibits evaporation of water and butanol, elimination of ethyl acetoacetate and butoxy groups, carbonate removal, anatase crystallization and transformation to rutile, accompanied with oxidation of carbonaceous species. After 2 h at 350 C pure nanocrystalline anatase crystallites were obtained having average crystallite size of 16.4 nm with majority of exposed {; ; ; ; ; ; 101}; ; ; ; ; ; facets.

anatase ; chelating agent ; hybrid nanoclusters ; mesoporous gel ; nanocrystals

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