Correction to Nanocrystals of Hematite with Unconventional Shape-Truncated Hexagonal Bipyramid and Its Optical and Magnetic Properties

Van, Thanh-Khue; Gil, Hyun; Nguyen, Cuc; Kim, Soo-Whan; Jung, Myung‐Hwa; Kang, Young Soo

doi:10.1021/cg300260g

Cited by 3 publications

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“…The addition of F – anions, 1-butyl-3-methylimidazolium tetrafluoroborate, or formamide resulted in the formation of α-Fe 2 O 3 nanoparticles with a hexagonal bipyramid shape. A similar morphology can also be grown using K 3 [Fe(CN) 6 ], N 2 H 4 and sodium carboxymethyl cellulose mixtures via the hydrothermal process. , …”

Section: Introductionmentioning

confidence: 99%

Hydrothermal Synthesis of Octadecahedral Hematite (α-Fe₂O₃) Nanoparticles: An Epitaxial Growth from Goethite (α-FeOOH)

et al. 2014

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Driven by the demand for shape-controlled synthesis of α-Fe 2 O 3 nanostructures and the understanding of their growth mechanism and shape-dependent properties, we report the synthesis of octadecahedral α-Fe 2 O 3 nanocrystals with a hexagonal bipyramid shape by introducing F − anions in the solution. The hydrothermal growth process from hydrolysis of Fe 3+ precursors involves three steps: the nucleation of akaganeite (β-FeOOH) nanorods, followed by the formation of goethite (α-FeOOH) crystals with acicular and twinned shapes, and a subsequent transformation into hematite (α-Fe 2 O 3 ) nanoparticles. The phase transformation and growth of α-Fe 2 O 3 particles from α-FeOOH follows dissolution of goethite and reprecipitation as hematite process. The initial nucleation of α-Fe 2 O 3 particles was found to form epitaxially on goethite {001} surfaces due to a perfect lattice match between goethite {001} surface and hematite {001} planes. The structural relationship between goethite and hematite is G(020)//H(030) with G[100]//H[100]. The obtained α-Fe 2 O 3 hexagonal bipyramid particles are enclosed by 12 {113} planes and six {104} facets. Since the twinned α-FeOOH particles are one of the typical shapes of intermediate goethite crystals, the nucleation of hematite particles on two twinned arms gives rise to the formation of twinned hematite particles. F − anions play an important role in the formation of α-Fe 2 O 3 particles with a hexagonal bipyramid shape because high concentration of F − anions can stabilize the exposed {113} surfaces. The controlled synthesis of α-Fe 2 O 3 nanoparticles with defined surfaces not only provides significant information on hematite surface structures and energies but also is critical to give the structure−property relationship for the application of hematite materials.

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Section: Introductionmentioning

confidence: 99%

Hydrothermal Synthesis of Octadecahedral Hematite (α-Fe₂O₃) Nanoparticles: An Epitaxial Growth from Goethite (α-FeOOH)

et al. 2014

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“…The presence of various ligands in solution during oxide particle synthesis and in particular hematite has a significant effect on morphology: truncated [14] and full hexagonal bipyramid [15], rods [16], and tubes [17] can be obtained ( Figure 10.2). Indeed, the morphology of a crystal depends on the growth rates of the different crystallographic planes.…”

Section: Versatility Of Hematite Morphologymentioning

confidence: 99%

“…Indeed, the morphology of a crystal depends on the growth rates of the different crystallographic planes. More energetic planes grow very fast, while Figure 10.2 Images of unconventional hematite morphology obtained using different capping agents, namely, (a) truncated hexagonal bipyramid synthesized with carboxymethyl cellulose and hydrazine molecules (with permission from [14], © 2012, American Chemical Society), (b) single-crystalline dodecahedral as hexagonal bipyramidal shape synthesized with the aid of F − anions (with permission from [15], © 2010 WILEY-VCH), (c) nanorods with high aspect ratios synthesized by 1,2-propanediamine-assisted hydrothermal method [16], and (d) single-crystalline hematite nanotubes fabricated by onestep hydrothermal method in an aqueous NH 4 H 2 PO 4 solution [17]. the less energetic ones are the slow-growing planes.…”

Section: Versatility Of Hematite Morphologymentioning

confidence: 99%

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Synthetic Formation of Iron Oxides

2016

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“…Hematite (α-Fe 2 O 3 ) is a very promising material for a wide range of applications, such as catalysis, gas sensors, medical applications, magnetic devices, energy storage and conversion devices, and so on, for its abundance, high stability, and environmental friendliness [ 21 – 24 ]. As is well known, the performance of a material is closely related to its nanoscopic morphology which, in turn, is governed by the synthetic method.…”

Section: Introductionmentioning

confidence: 99%

Hematite Thin Films with Various Nanoscopic Morphologies Through Control of Self-Assembly Structures

2015

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Hematite (α-Fe2O3) thin films with various nanostructures were synthesized through self-assembly between iron oxide hydroxide particles, generated by hydrolysis and condensation of Fe(NO3)3 · 6H2O, and a Pluronic triblock copolymer (F127, (EO)106(PO)70(EO)106, EO = ethylene oxide, PO = propylene oxide), followed by calcination. The self-assembly structure can be tuned by introducing water in a controlled manner through the control of the humidity level in the surrounding of the as-cast films during aging stage. For the given Fe(NO3)3 · 6H2O:F127 ratio, there appear to be three different thermodynamically stable self-assembly structures depending on the water content in the film material, which correspond to mesoporous, spherical micellar, and rod-like micellar structures after removal of F127. Coupled with the thermodynamic driving forces, the kinetics of the irreversible reactions of coalescence of iron oxide hydroxide particles into larger ones induce diverse nanostructures of the resultant films. The length scale of so-obtained nanostructures ranges from 6 nm to a few hundred nanometers. In addition to water content, the effects of other experimental parameters such as aging temperature, spin rate during spin coating, type of substrate, and type of iron reagent were investigated.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-015-0936-x) contains supplementary material, which is available to authorized users.

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Correction to Nanocrystals of Hematite with Unconventional Shape-Truncated Hexagonal Bipyramid and Its Optical and Magnetic Properties

Cited by 3 publications

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Hydrothermal Synthesis of Octadecahedral Hematite (α-Fe₂O₃) Nanoparticles: An Epitaxial Growth from Goethite (α-FeOOH)

Hydrothermal Synthesis of Octadecahedral Hematite (α-Fe₂O₃) Nanoparticles: An Epitaxial Growth from Goethite (α-FeOOH)

Synthetic Formation of Iron Oxides

Hematite Thin Films with Various Nanoscopic Morphologies Through Control of Self-Assembly Structures

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Correction to Nanocrystals of Hematite with Unconventional Shape-Truncated Hexagonal Bipyramid and Its Optical and Magnetic Properties

Cited by 3 publications

References 0 publications

Hydrothermal Synthesis of Octadecahedral Hematite (α-Fe2O3) Nanoparticles: An Epitaxial Growth from Goethite (α-FeOOH)

Hydrothermal Synthesis of Octadecahedral Hematite (α-Fe2O3) Nanoparticles: An Epitaxial Growth from Goethite (α-FeOOH)

Synthetic Formation of Iron Oxides

Hematite Thin Films with Various Nanoscopic Morphologies Through Control of Self-Assembly Structures

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Product

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Hydrothermal Synthesis of Octadecahedral Hematite (α-Fe₂O₃) Nanoparticles: An Epitaxial Growth from Goethite (α-FeOOH)

Hydrothermal Synthesis of Octadecahedral Hematite (α-Fe₂O₃) Nanoparticles: An Epitaxial Growth from Goethite (α-FeOOH)