Metallic iron nanoparticles: Flame synthesis, characterization and magnetic properties--颗粒学报PARTICUOLOGY

Li, Y., Hu, Y., Huang, G., & Li, C. (2013). Metallic iron nanoparticles: Flame synthesis, characterization and magnetic properties. Particuology, 11(4), 460–467. https://doi.org/10.1016/j.partic.2012.10.008

Metallic iron nanoparticles: Flame synthesis, characterization and magnetic properties

Yunfeng Li ^a, Yanjie Hu ^a, Guangjian Huang ^b, Chunzhong Li ^a *

a Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science & Technology, Shanghai 200237, China
b Department of Surgery, Huashan Hospital, Fudan University, Shanghai 200040, China

10.1016/j.partic.2012.10.008

Volume 11, Issue 4, August 2013, Pages 460-467

Received 1 August 2012, Revised 9 October 2012, Accepted 14 October 2012, Available online 7 May 2013.

E-mail: czli@ecust.edu.cn

Highlights

• Core–shell metallic Fe nanoparticles were synthesized via flame spray pyrolysis.

• Iron core and Fe₃O₄ shell were obtained via tailoring residence time and atmosphere in flame.

• Formation of metallic Fe in flame may be attributed to strong reducing atmosphere.

• Competition mechanism between reducing and oxidizing flames were proposed.

Abstract

Metallic iron (Fe) nanoparticles (NPs) with a typical core–shell structure have been prepared by a simple and continuous flame spray pyrolysis (FSP) method, which are stabilized by the corresponding Fe₃O₄ shell with a thickness of 4–6 nm. The size of metallic Fe cores is about 30–80 nm. The core–shell structured iron NPs show an air stability as long as one month as a result of the protection of oxide shell. Through the control of the residence time of materials in flame and flame atmosphere, metallic Fe and iron oxides are obtained, showing a better external magnetic field responsibility. It is concluded that the evolution of morphology and composition of flame-made magnetic NPs could be attributed to the competition mechanism between reduction and oxidation reactions of in situ flame combustion, which offers more choices and better effective design strategy for the synthesis of advanced functional materials via FSP techniques.

Graphical abstract

Keywords

Iron NPs; FSP; Reducing flame; Magnetic properties

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