In situ high-temperature X-ray diffraction study of Sc-doped titanium oxide nanocrystallites

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388980%3A_____%2F20%3A00535911" target="_blank" >RIV/61388980:_____/20:00535911 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1107/S1600576720012017" target="_blank" >https://doi.org/10.1107/S1600576720012017</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1107/S1600576720012017" target="_blank" >10.1107/S1600576720012017</a>

Result language

angličtina

Original language name

In situ high-temperature X-ray diffraction study of Sc-doped titanium oxide nanocrystallites

Original language description

Titanium dioxide is an inexpensive wide-gap highly ionic semiconductor with striking photocatalytic capabilities in several heterogeneous photoredox reactions. A small crystal size is desirable to maximize the surface area, since photocatalytic reactions occur at the surface of a photocatalyst. Presented here are the synthesis and microstructural characterization of 4 at.% Sc-doped TiO2 (4SDT) prepared by water-based co-precipitation. The crystal structure of 4SDT was examined via in situ high-temperature powder X-ray diffraction experiments from 25 to 1200°C. Rietveld analysis revealed single-phase anatase up to 875°C, while at 900°C the anatase-to-rutile phase transformation occurred and at higher temperatures additional reflections of Sc-rich phases (Sc2TiO5 from 975°C and Ti3Sc4O12 or Sc2O3 at 1200°C) were observed. Debye function analysis (DFA) was applied to model the total scattering pattern directly in reciprocal space, allowing the reconstruction of Ti vacancies. Both Rietveld and DFA methods were applied to estimate the nanocrystallite size and shape with consistent growth in crystallite size with temperature: an ellipsoid shape with equatorial ∼4.7 nm / axial (001) ∼6.9 nm at 25°C to equatorial ∼27.9 nm / axial (001) ∼39.6 nm at 900°C refined by Rietveld analysis, versus a cylinder shape with Da,b = 4.3 nm and size dispersion σab = 1.5 nm, Lc = 4.9 nm and σc = 2.3 nm at 25°C to Da,b = 21.4 nm, σab = 8.3 nm, Lc = 23.9 and σc = 10.9 nm at 900°C estimated by DFA. The microstructural changes obtained by Rietveld and DFA methods were supported by high-resolution transmission electron microscopy image analysis, as well as by the less direct nitrogen sorption techniques that provide information on the size of non-agglomerated and dense particles. The Ti site-occupancy factor showed a linear increase from 0.6–0.8 at 25°C to unity at 900°C for anatase, and from ∼0.7 at 900°C to unity at 1200°C for rutile, via Rietveld analysis and DFA.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

<a href="/en/project/GA18-15613S" target="_blank" >GA18-15613S: Integrating plasmonic metal nanoparticles with photonic TiO2 nanosheets for synergistically water splitting and environmental photocatalysis</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Applied Crystallography

ISSN

1600-5767

e-ISSN

—

Volume of the periodical

53

Issue of the periodical within the volume

6

Country of publishing house

GB - UNITED KINGDOM

Number of pages

10

Pages from-to

1452-1461

UT code for WoS article

000595702500006

EID of the result in the Scopus database

2-s2.0-85097303651