Mechano-thermal synthesis and characterization of nano-structured Fe/FeS for application in photocatalysis--颗粒学报PARTICUOLOGY

Esmaili, H., Sheibani, S., & Rashchi, F. (2018). Mechano-thermal synthesis and characterization of nano-structured Fe/FeS for application in photocatalysis. Particuology, 37, 72-80. https://doi.org/10.1016/j.partic.2017.07.005

Mechano-thermal synthesis and characterization of nano-structured Fe/FeS for application in photocatalysis

H. Esmaili, S. Sheibani ^*, F. Rashchi

School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran 11155-4563, Iran

10.1016/j.partic.2017.07.005

Volume 37, April 2018, Pages 72-80

Received 13 February 2017, Revised 20 June 2017, Accepted 3 July 2017, Available online 21 November 2017, Version of Record 3 February 2018.

E-mail: ssheibani@ut.ac.ir

Highlights

• Fe/FeS core/shell nano-structure was synthesized by mechano-thermal method.

• Approximately 2 nm of FeS shell was formed on the Fe core.

• Mechanism of transformation was studied by differential scanning calorimetry.

• Mechanical activation and NaCl addition led to decrease of M_s value.

Abstract

A novel method was used to prepare a nano-structured 32 wt% Fe/FeS core/shell powder via a mechano-thermal route by 1-h heat treatment of a mechanically activated powder mixture of Fe and S. The structural and microstructural characteristics, formation mechanism, magnetic properties, and photocatalytic activity of the powder were studied by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, surface area analysis, differential scanning calorimetry, vibrating sample magnetometry, and UV–vis spectrophotometry. A detailed study of the mechanism of transformation showed that during the heat treatment process, an FeS₂ phase was formed as the intermediate product. In the final product, an FeS shell approximately 2 nm in thickness was formed on the Fe core. In the presence of NaCl as a process control agent, the particle size decreased and the size distribution became more uniform. Mechanical activation and NaCl addition together led to a decrease of the saturation magnetization from 82 to 74 emu/g. The photocatalytic activity of the powder in the degradation of methylene blue was 50%.

Graphical abstract

Keywords

Fe/FeS; Core–shell; Mechano-thermal; Nano-structure; Photocatalyst

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