A mild one-step solvothermal route to truncated octahedral magnetite crystals--颗粒学报PARTICUOLOGY

Zhang, D., Shang, L., Shen, J., Shi, Z., Wu, L., Tung, C., & Zhang, T. (2014). A mild one-step solvothermal route to truncated octahedral magnetite crystals. Particuology, 15, 51–55. https://doi.org/10.1016/j.partic.2013.02.015

A mild one-step solvothermal route to truncated octahedral magnetite crystals

Donghui Zhang ^a, Lu Shang ^{a b}, Jun Shen ^a, Zhan Shi ^c, Lizhu Wu ^a, Chenho Tung ^a, Tierui Zhang^a *

a Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
b University of Chinese Academy of Sciences, Beijing 100049, China
c State Key Laboratory of Inorganic Synthesis & Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China

10.1016/j.partic.2013.02.015

Volume 15, August 2014, Pages 51-55

Received 9 November 2012, Revised 1 February 2013, Accepted 26 February 2013, Available online 6 August 2013.

E-mail: tierui@mail.ipc.ac.cn

Highlights

• Truncated octahedral magnetite was synthesized through mild solvothermal method.

• 160 °C is optimum for the formation of truncated octahedra.

• An appropriate amount of NaOH is helpful at mild temperature.

• The as-prepared magnetite is ferromagnetic with an Ms value of 83 emu/g at room temperature.

Abstract

Perfect truncated octahedral magnetite crystals were successfully synthesized from FeCl₃·6H₂O and poly(acrylic acid) (PAA) in an alkaline ethylene glycol solution via a mild one-step solvothermal process. The structure and morphologies of the obtained products were characterized by powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effects of synthetic parameters including reaction temperature, reaction time, and the amount of alkali on the morphological evolution of the truncated octahedral magnetite crystals were systematically explored. 160 °C was found to be the optimum temperature for the formation of truncated octahedral magnetite crystals. Below 160 °C, little magnetite was formed. Above 160 °C, the truncated octahedrons were gradually transformed into irregular-shaped polyhedrons. Alkali is indispensable in promoting the formation of magnetite at mild temperatures. The truncated octahedral magnetite crystals were found to be ferromagnetic and had a saturation magnetization of about 83 emu/g.

Graphical abstract

Keywords

Truncated octahedron; Magnetite; Solvothermal synthesis; Magnetic; Energy storage

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