Nano-micro-architectural composites with acid properties: Magnetic iron oxides/amorphous silicate prepared from iron oxide produced by iron-oxidizing bacterium, Leptothrix ochracea

Hideki Hashimoto, Atsushi Itadani, Tatsuo Fujii, Makoto Nakanishi, Hiroshi Asaoka, Yoshihiro Kusano, Yasunori Ikeda, Yasushige Kuroda, Jun Takada

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

To develop novel magnetic composites with acid functionalities, iron oxide produced by iron-oxidizing bacterium, Leptothrix ochracea, was used as a precursor. The composites were prepared by thermal treatment and subsequent reduction of the bacterial iron oxide. α-Fe2O3 nanoparticles obtained in air were thermally reduced to Fe3O 4 and gradually oxidized to γ-Fe2O3. The obtained composites with Fe3O4 and γ-Fe 2O3 have high magnetization values that are approximately half those of pure Fe3O4 and γ-Fe2O 3. All samples have an interesting nano-micro-architectural structure: ∼40-nm-diameter crystalline particles covered with ∼8-nm-thick amorphous silicate are intricately interconnected into ∼1-μm-diameter microtubules. Pyridine adsorption spectra indicate that the surface amorphous silicate has both Brönsted and Lewis acid properties.

Original languageEnglish
Pages (from-to)1174-1177
Number of pages4
JournalMaterials Research Bulletin
Volume48
Issue number3
DOIs
Publication statusPublished - Mar 1 2013

Keywords

  • A. Amorphous Materials
  • A. Composites
  • A. Magnetic materials
  • A. Nanostructures
  • D. Microstructure

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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