Hematite template route to hollow-type silica spheres

Journal Article · Mon Oct 15 00:00:00 EDT 2007 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.08.016· OSTI ID:21049534

Han, Yang-Su ^[1]; Jeong, Gee-Young ^[1]; Lee, Sun-Young ^[1]; Kim, Ho-Kun ^[2]

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1. Nanomaterial Laboratory, Nanospace Co. Ltd., Ansan Digital Park 6032, 1123 Singgil-dong, Danwon-gu, Ansan, Gyunggi-do 425-839 (Korea, Republic of)
2. Department of Applied Chemistry, Hanyang University, Sa-1-dong, Sangnok-gu, Ansan 425-791 (Korea, Republic of)

Hollow-type silica spheres with controlled cavity size were prepared from Fe{sub 2}O{sub 3}-SiO{sub 2} core-shell composite particles by selective leaching of the iron oxide core materials using acidic solution. The spherical Fe{sub 2}O{sub 3} core particles with a diameter range of 20-400 nm were first prepared by the hydrolysis reaction of iron salts. Next, the Fe{sub 2}O{sub 3}-SiO{sub 2} core-shell particles were prepared by the deposition of a SiO{sub 2} layer onto the surface of Fe{sub 2}O{sub 3} particles using a two-step coating process, consisting of a primary coating with sodium silicate solution and a subsequent coating by controlled hydrolysis of tetraethoxysilicate (TEOS). The Fe{sub 2}O{sub 3} core was then removed by dissolving with acidic solution, giving rise to hollow-type silica particles. Scanning electron microscopy clearly revealed that the cavity size was closely related to the initial size of the core Fe{sub 2}O{sub 3} particle. According to the cross-sectional view obtained by transmission electron microscopy, the silica shell thickness was about 10 nm. The porous texture of the hollow-type silica particles was further characterized by nitrogen adsorption-desorption isotherm measurements. - Graphical abstract: TEM micrograph of the hollow silica particles. Wall thickness, as estimated by TEM from the ring around the perimeter of the hollow spheres, was {approx}10 nm. TEM micrographs of hollow silica spheres show that the sphericity of the core Fe{sub 2}O{sub 3} was preserved.

• OSTI ID: 21049534
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 10 Vol. 180; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ADSORPTION
DESORPTION
HEMATITE
HYDROLYSIS
IRON OXIDES
ISOTHERMS
LAYERS
LEACHING
NITROGEN
POROUS MATERIALS
SCANNING ELECTRON MICROSCOPY
SILICA
SILICON OXIDES
SODIUM SILICATES
SOLUTIONS
SPHERICAL CONFIGURATION
SURFACE COATING
SURFACES
TRANSMISSION ELECTRON MICROSCOPY