Controlled synthesis of hollow magnetic Fe3O4 nanospheres: Effect of the cooling rate--颗粒学报PARTICUOLOGY

Hong, Y., Shi, H., Shu, X., Zheng, Y., Zhang, Y., & Wu, Y. (2017). Controlled synthesis of hollow magnetic Fe3O4 nanospheres: Effect of the cooling rate. Particuology, 33, 24-28. https://doi.org/10.1016/j.partic.2016.10.002

Controlled synthesis of hollow magnetic Fe₃O₄ nanospheres: Effect of the cooling rate

Yong Hong ^{a b}, Hongbing Shi ^b, Xia Shu ^a *, Yuchun Zheng ^a, Yong Zhang ^{a c}, Yucheng Wu ^{a c *}

a School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China
b Anhui Special Equipment Inspection Institute, Hefei 230051, China
c Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, Hefei 230009, China

10.1016/j.partic.2016.10.002

Volume 33, August 2017, Pages 24-28

Received 23 July 2016, Revised 29 September 2016, Accepted 10 October 2016, Available online 5 February 2017, Version of Record 13 June 2017.

E-mail: Shuxia318@163.com; ycwu@hfut.edu.cn

Highlights

• Effect of cooling rate on the growth of Fe₃O₄ nanospheres was investigated.

• Higher cooling rate improved crystallinity and magnetic properties of the nanospheres.

• Growth mechanism of the hollow magnetite oxide nanospheres was proposed.

• Correlation between the structure and magnetic property of the nanospheres was discussed.

Abstract

The controlled synthesis of hollow magnetite (Fe₃O₄) nanospheres of varying sizes and structures was successfully obtained via a facile solvothermal process and varying cooling processes. The Fe₃O₄ nanospheres were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and superconducting quantum interference device magnetometry. The diameters of the as-synthesized nanospheres were controlled at around 500–700 nm by simply changing the cooling rate, which had an obvious influence on the morphology and magnetic properties of these Fe₃O₄ nanospheres. While a low cooling rate triggered the formation and extension of the cracks present in the Fe₃O₄ nanospheres, a sudden drop of temperature tended to favor multi-site nucleation of the crystals as well as the formation of compact and smooth hollow nanospheres with superior crystallinity and high saturation magnetization. The growth mechanism of hollow magnetite oxide nanospheres was proposed and the correlation between the structure and the magnetic properties of the hollow nanospheres was discussed, which promises the potential of the hollow nanospheres in various applications such as drug delivery and cell separation.

Graphical abstract

Keywords

Solvothermal method; Fe₃O₄ nanosphere; Hollow structure; Cooling rate; Magnetic property

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