High-temperature stability and phase transformations of titanium carbide (Ti 3 C 2 T x ) MXene.

Autor:	Wyatt BC; Department of Mechanical and Energy Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America.; Integrated Nanosystems Development Institute, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America., Nemani SK; Department of Mechanical and Energy Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America.; Integrated Nanosystems Development Institute, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America., Desai K; Department of Mechanical and Energy Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America., Kaur H; Department of Mechanical and Energy Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America.; Department of Biology, Purdue School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America., Zhang B; Department of Mechanical and Energy Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America.; Integrated Nanosystems Development Institute, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America.; Henan Key Laboratory of Photovoltaic Materials, Henan University, Kaifeng 475004, People's Republic of China., Anasori B; Department of Mechanical and Energy Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America.; Integrated Nanosystems Development Institute, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, United States of America.
Jazyk:	angličtina
Zdroj:	Journal of physics. Condensed matter : an Institute of Physics journal [J Phys Condens Matter] 2021 May 05; Vol. 33 (22). Date of Electronic Publication: 2021 May 05.
DOI:	10.1088/1361-648X/abe793
Abstrakt:	Two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides, known as MXenes, are under increasing pressure to meet technological demands in high-temperature applications, as MXenes can be considered to be one of the few ultra-high temperature 2D materials. Although there are studies on the stability of their surface functionalities, there is currently a gap in the fundamental understanding of their phase stability and transformation of MXenes' metal carbide core at high temperatures (>700 °C) in an inert environment. In this study, we conduct systematic annealing of Ti 3 C 2 T x MXene films in which we present the 2D MXene flake phase transformation to ordered vacancy superstructure of a bulk three-dimensional (3D) Ti 2 C and TiC y crystals at 700 °C ⩽ T ⩽ 1000 °C with subsequent transformation to disordered carbon vacancy cubic TiC y at higher temperatures ( T > 1000 °C). We annealed Ti 3 C 2 T x MXene films made from the delaminated MXene single-flakes as well as the multi-layer MXene clay in a controlled environment through the use of in situ hot stage x-ray diffraction (XRD) paired with a 2D detector (XRD 2 ) up to 1000 °C and ex situ annealing in a tube furnace and spark plasma sintering up to 1500 °C. Our XRD 2 analysis paired with cross-sectional scanning electron microscope imaging indicated the resulting nano-sized lamellar and micron-sized cubic grain morphology of the 3D crystals depend on the starting Ti 3 C 2 T x form. While annealing the multi-layer clay Ti 3 C 2 T x MXene creates TiC y grains with cubic and irregular morphology, the grains of 3D Ti 2 C and TiC y formed by annealing Ti 3 C 2 T x MXene single-flake films keep MXenes' lamellar morphology. The ultrathin lamellar nature of the 3D grains formed at temperatures >1000 °C can pave way for applications of MXenes as a stable carbide material 2D additive for high-temperature applications. (© 2021 IOP Publishing Ltd.)
Databáze:	MEDLINE
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