Preparation of a new pyrochlore-type compound Na{sub 0.32}Bi{sub 1.68}Ti{sub 2}O{sub 6.46}(OH){sub 0.44} by hydrothermal reaction

Journal Article · Fri Jul 15 04:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.04.035· OSTI ID:21580143

Qiang, Dong; Hong, Jiang ^[1]; Kumada, Nobuhiro ^[1]; Yonesaki, Yoshinori; Takei, Takahiro; Kinomura, Nobukazu ^[1]

---

1. Department of Research Interdisciplinary, Graduate School of Medicine and Engineering, University of Yamanashi, Miyamae cho-7, Kofu 400-8511 (Japan)

A new pyrochlore-type Na{sub 0.32}Bi{sub 1.68}Ti{sub 2}O{sub 6.46}(OH){sub 0.44} with the cubic cell of a=10.339(5) A was prepared by hydrothermal reaction using TiO{sub 2} (anatase) and Bi{sub 2}O{sub 3} in NaOH solution. This compound was obtained when the molar ratio of NaOH/TiO{sub 2} was above 2 and the reaction temperature was above 240 deg. C. The TG-curve of as-prepared sample showed a mass loss of 0.8 mass% which was caused by release of OH group. This compound decomposed to a pyrochlore-type compound and a layered-type Na{sub 0.5}Bi{sub 4.5}Ti{sub 4}O{sub 15} above 800 deg. C. The optical band gap of Na{sub 0.32}Bi{sub 1.68}Ti{sub 2}O{sub 6.46}(OH){sub 0.44} was estimated to be 2.5 eV. - Graphical abstract: SEM image and schematic representation of the structure of Na{sub 0.32}Bi{sub 1.68}Ti{sub 2}O{sub 6.46} (OH){sub 0.44}. Highlights: > A new pyrochlore-type Na{sub 0.32}Bi{sub 1.68}Ti{sub 2}O{sub 6.46}(OH){sub 0.44} is first prepared via a facile hydrothermal route. > The chemical composition is concluded to be Na{sub 0.32}Bi{sub 1.68}Ti{sub 2}O{sub 6.46}(OH){sub 0.44} from the analysis of experimental results. > The crystal data and atomic parameters can compare with those of pyrochlore-type bismuth titanates.

• OSTI ID: 21580143
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 7 Vol. 184; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BISMUTH
BISMUTH COMPOUNDS
BISMUTH OXIDES
CHALCOGENIDES
CHEMICAL COMPOSITION
CRYSTALS
ELECTRON MICROSCOPY
ELEMENTS
HYDROTHERMAL SYNTHESIS
METALS
MICROSCOPY
MINERALS
OXIDES
OXYGEN COMPOUNDS
PYROCHLORE
SCANNING ELECTRON MICROSCOPY
SYNTHESIS
TITANATES
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS