Morphology, chemical composition and phase transformation of hydrothermal derived sodium Titanate

Meng Jung Li, Zuo Yun Chi, Yu Chun Wu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

26 Citations (Scopus)

Abstract

This study intends to clarify the discrepancies on the effect of precursor size, chemical composition, and thermal behavior of Na-titanate obtained through a conventional hydrothermal reaction of anatase in a highly concentrated aqueous NaOH solution. According to experimental results, as well as that presented in related literatures, ultrafine anatase precursor favors nanofiber formation, whereas larger-particle anatase precursor forms nanotubes. The formation mechanism, in correlation with the precursor size and the resulting morphology of the obtained titanate product, is described in detail. According to X-ray Diffraction and Raman analyses, the as-formed Na-titanate is considered a quasi-disordered structure that allows the occupation of a wide range of Na into the titanate structure. An increased Na/Ti ratio is observed with increased temperature, which simultaneously results in a distortion of the titanate structure. Moreover, the as-synthesized Na-titanate is thermally unstable and tends to degrade into amorphous clusters after heat treatment at 300°C. Rod-like Na 2Ti 6O 13 is recrystallized from the amorphous cluster at 700°C-800°C and becomes plate-like after annealing at 900°C via a parallel assembly of Na 2Ti 6O 13 rods. An additional Na 2Ti 3O 7 phase appears at high temperatures, exhibiting a relatively higher Na/Ti ratio.

Original languageEnglish
Pages (from-to)3297-3304
Number of pages8
JournalJournal of the American Ceramic Society
Volume95
Issue number10
DOIs
Publication statusPublished - Oct 2012
Externally publishedYes

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

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