A Raman spectroscopic study on the active site of sodium cations in the structure of Na2Ti3O7 during the adsorption of Sr2+ and Ba2+ cations

Authors

  • Hongwei Liu,

    1. Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD 4001, Australia
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  • Dongjiang Yang,

    1. Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD 4001, Australia
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  • Eric R. Waclawik,

    1. Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD 4001, Australia
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  • Xuebin Ke,

    1. Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD 4001, Australia
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  • Zhanfeng Zheng,

    1. Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD 4001, Australia
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  • Huaiyong Zhu,

    1. Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD 4001, Australia
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  • Ray L. Frost

    Corresponding author
    1. Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD 4001, Australia
    • Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD 4001, Australia.
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Abstract

A detailed study on the structural deformation of trititanate nanofibers after the adsorption of divalent strontium (Sr) and barium (Ba) cations was conducted by using Raman spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that the Raman bands at 309 cm−1 corresponding to very long Ti[BOND]O bonds (2.2 Å) and at 883 cm−1 corresponding to the very short Ti[BOND]O bonds (1.7 Å) decreased in intensity after the adsorption of Ba2+ and Sr2+ cations. Additionally, the band at 922 cm−1 corresponding to an intermediate length Ti[BOND]O bond was observed to weaken with the adsorption of divalent cations, indicating that the TiO6 octahedra in Na2Ti3O7 are more regular. These results suggest that the active sodium (Na+) cations in Na2Ti3O7 should be located at the corner of the TiO6 octahedral slabs, i.e. the plane (003). This was further confirmed by a large decrease of diffraction intensity of the plane (003) observed in the XRD pattern. Copyright © 2010 John Wiley & Sons, Ltd.

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