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

Autor:	Yoshihiro Kusano, Makoto Nakanishi, Tatsuo Fujii, Yasunori Ikeda, Yasushige Kuroda, Jun Takada, Hiroshi Asaoka, Hideki Hashimoto, Atsushi Itadani
Rok vydání:	2013
Předmět:	Materials science Mechanical Engineering Iron oxide Nanoparticle Thermal treatment Condensed Matter Physics Silicate Amorphous solid chemistry.chemical_compound Adsorption chemistry Mechanics of Materials Pyridine Oxidizing agent General Materials Science Composite material
Zdroj:	Materials Research Bulletin. 48:1174-1177
ISSN:	0025-5408
Popis:	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-Fe 2 O 3 nanoparticles obtained in air were thermally reduced to Fe 3 O 4 and gradually oxidized to γ-Fe 2 O 3 . The obtained composites with Fe 3 O 4 and γ-Fe 2 O 3 have high magnetization values that are approximately half those of pure Fe 3 O 4 and γ-Fe 2 O 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 Bronsted and Lewis acid properties.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::68063eda969f27c9b2035cf48c600608 https://doi.org/10.1016/j.materresbull.2012.12.022 Zobrazit plný text záznamu Full Text from ScienceDirect