Chemical synthesis of unique intermetallic TiFe nanostructures originating from the morphology of oxide precursors

Yasukazu Kobayashi; Heng Yi Teah; Nobuko Hanada

doi:10.1039/d1na00251a

Chemical synthesis of unique intermetallic TiFe nanostructures originating from the morphology of oxide precursors

Nanoscale Adv. 2021 Jul 13;3(18):5284-5291. doi: 10.1039/d1na00251a. eCollection 2021 Sep 14.

Authors

Yasukazu Kobayashi¹, Heng Yi Teah², Nobuko Hanada³

Affiliations

¹ Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST) 1-1-1 Higashi Tsukuba Ibaraki 305-8565 Japan yasu-kobayashi@aist.go.jp.
² Waseda Research Institute for Science and Engineering, Waseda University Tokyo 169-8555 Japan.
³ Department of Applied Chemistry, Waseda University 3-4-1 Okubo, Shinjuku-ku Tokyo 169-8555 Japan.

Abstract

In this study, intermetallic TiFe nanostructures were chemically prepared from Ti-Fe oxide precursors using a CaH₂ reducing agent in molten LiCl at as low as 600 °C. The used precursor was spherical oxide nanoparticles or commercial FeTiO₃ bulk powder. After the reduction treatment, the former precursor was changed to an aggregation of TiFe nanoparticles with a particle size of 44-46 nm. Surprisingly, the latter precursor was reduced to a layered morphology composed of TiFe nanoparticles with a particle size of 47-65 nm. An intermetallic compound with a unique layered morphology was found for the first time, and the layered morphology could have originated from the morphology of the FeTiO₃ precursor in which the Fe²⁺ and Ti⁴⁺ ions occupied alternating layers perpendicular to the trigonal c-axis. The precursor originated morphology was enabled by the proposed low reduction temperature method, and the environment-friendliness of the proposed method was finally evaluated using life-cycle assessment (LCA).