Synthesis of mesoporous γ-AlOOH@Fe3O4 magnetic nanomicrospheres--颗粒学报PARTICUOLOGY

Zheng, Y., Ji, S., Liu, H., Li, M., & Yang, H. (2012). Synthesis of mesoporous γ-AlOOH@Fe3O4 magnetic nanomicrospheres. Particuology, 10(6), 751–758. https://doi.org/10.1016/j.partic.2012.04.003

Synthesis of mesoporous γ-AlOOH@Fe₃O₄ magnetic nanomicrospheres

Yuanyuan Zheng, Shengfu Ji^*, Hongfei Liu, Ming Li, Hao Yang

State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China

10.1016/j.partic.2012.04.003

Volume 10, Issue 6, December 2012, Pages 751-758

Received 9 November 2011, Revised 13 April 2012, Accepted 16 April 2012, Available online 9 June 2012.

E-mail: jisf@mail.buct.edu.cn

Highlights

► Mesoporous γ-AlOOH@Fe₃O₄ magnetic nanomicrospheres were synthesized consisting of a mesoporous γ-AlOOH shell and a Fe₃O₄ magnetic core.

► Diameter of γ-AlOOH@Fe₃O₄ was about 200 nm, the thickness of γ-AlOOH shell was about 5 nm with average pore size of 3.8 nm.

► Thickness of mesoporous γ-AlOOH can be controlled via layer-by-layer coating.

Abstract

Mesoporous γ-AlOOH@Fe₃O₄ magnetic nanomicrospheres were synthesized using superparamagnetic Fe3O4 nanoparticles as the core and aluminum isopropoxide (AIP) as the aluminum source. The obtained magnetic nanomicrospheres were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N₂ adsorption–desorption and vibrating sample magnetometry (VSM). The effects of preparation parameters such as hydrolysis time of AIP, concentration of AIP and coating layer number on microspheres were investigated. The results indicated that the mesoporous γ-AlOOH@Fe₃O₄ magnetic nanomicrospheres consisted of a mesoporous γ-AlOOH shell and a Fe₃O₄ magnetic core. The diameter of γ-AlOOH@Fe₃O₄ nanomicrospheres was about 200 nm, the thickness of mesoporous γ-AlOOH shell was about 5 nm and the average pore size was 3.8 nm. The thickness of the mesoporous γ-AlOOH shell could be controlled via layer-by-layer coating times. The formation mechanism of the mesoporous γ-AlOOH shell involved a “chemisorption–hydrolysis” process.

Graphical abstract

Keywords

Magnetic nanomicrospheres; Fe₃O₄; γ-AlOOH shell; Mesoporous; Hydrolysis

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