Ammonium mediated hydrothermal synthesis of nanostructured hematite (α-Fe{sub 2}O{sub 3}) particles

Journal Article · Sat Sep 15 04:00:00 EDT 2012 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2012.05.005· OSTI ID:22215744

Wang, Xiaoge ^[1]

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1. Zhejiang Test Academy of Quality and Technical Supervision, Hangzhou 310013 (China)

Highlights: ► Hydrothermal synthesis of nanostructured hematite (α-Fe{sub 2}O{sub 3}) particles. ► NH{sub 4}OH mediated direct transformation of micro-rod hematite to ellipsoidal particles. ► Ellipsoids formed by controlled aggregation, rather than directional growth. -- Abstract: Uniform α-Fe{sub 2}O{sub 3} particles of different shapes have been synthesized through hydrothermal process. The additives, the type of Fe(III) salts and reaction conditions in hydrothermal process were thoroughly investigated. The crystalline structure and morphology of the as-synthesized powder have been characterized by using X-ray powder diffraction, scanning electron microscopy and field emission scanning electron microscopy. Rod and ellipsoidal-shaped α-Fe{sub 2}O{sub 3} were obtained with ferric chloride as a precursor, while only irregular-shaped particles were synthesized by using ferric nitrate as precursors in the absence of NH{sub 4}OH. Direct transformation of micro-rod hematite to ellipsoidal particles with FeCl{sub 3} as precursor was also observed by adding NH{sub 4}OH. It is shown that the nanorod was formed through presumed directional aggregation of rapidly formed nucleus, while the formation of ellipsoidal hematite particles may undergo a nucleation–aggregation–dissolution–recrystallization process in the presence of ammonium.

• OSTI ID: 22215744
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 9 Vol. 47; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
AMMONIUM HYDROXIDES
FERRITES
FIELD EMISSION
HEMATITE
HYDROTHERMAL SYNTHESIS
IRON CHLORIDES
IRON OXIDES
NANOSTRUCTURES
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
X-RAY DIFFRACTION