Highly conductive nano-sized Magnéli phases titanium oxide (TiOx)
SciRep_7_3646.pdf 2.4 MB
Arif, Aditya F
Okuyama, Kikuo 大学院工学研究院
Despite the strong recent revival of Magnéli phase TiOx as a promising conductive material, synthesis of Magnéli phase TiOx nanoparticles has been a challenge because of the heavy sintering nature of TiO2 at elevated temperatures. We have successfully synthesized chain-structured Magnéli phases TiOx with diameters under 30 nm using a thermal-induced plasma process. The synthesized nanoparticles consisted of a mixture of several Magnéli phases. A post-synthesis heat-treatment was performed to reduce the electrical resistivity without changing the particle morphology. The resistivity of the heat-treated particle was as low as 0.04 Ω.cm, with a specific surface area of 52.9 m2 g−1. The effects of heat-treatment on changes in the crystal structure and their correlation with the electron conductivity are discussed based on transmission electron microscopy images, X-ray diffraction spectra, and X-ray adsorption fine structure spectra. Electrochemical characterization using cyclic voltammetry and potentiodynamic scan shows a remarkable electrochemical stability in a strongly oxidizing environment.
This work was partially supported by a Hosokawa Grant for Promising Researchers from Hosokawa Powder Technology Foundation, JSPS KAKENHI Grant Numbers 2670906, Grant-in-Aid for Young Scientists B (15K182570A), and Center for Functional Nano Oxide at Hiroshima University.
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