ISSN:
1600-5775
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
Nano-sized titanium dioxides are incorporated into the interlayer spaces of ion-exchangeable layered perovskites, H1-xCa2-xLaxNb3O10 (x=0.00̃.75), by replacing the interlayer protons with positively charged TiO2 nano-sol particles or basic titanium glycolate complex (titanatrane). Powder X-ray diffraction analysis, UV-Vis absorption spectroscopy, thermogravimetric analysis, and N2 adsorption-desorption isotherm measurements show that quantum sized TiO2 particles are stabilized inbetween perovskite lattices to form micropores (SBET= 371̃10 m2/g). X-ray absorption spectroscopy at the Ti K-edge was used for investigating the local environment around Ti atoms constituting the interlayer pillars. According to the XANES spectra, the 'as-pillared' Ti species have the same local environments with those of precursory species, which subsequently converted into TiO2 clusters with rutile and anatase-like local structures when TiO2 nano-sol particles and titanatrane are used as pillaring species, respectively. It is also found that the local environment of TiO2 remains almost constant irrespective of the layer charge density, while the TiO2 pillar content and the microporosity increase with the latter.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S090904950100022X
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