Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes

doi:10.1126/science.aba8311

GSTDTAP > 气候变化

DOI	10.1126/science.aba8311
	Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes
	Vladislav Kamysbayev; Alexander S. Filatov; Huicheng Hu; Xue Rui; Francisco Lagunas; Di Wang; Robert F. Klie; Dmitri V. Talapin
	2020-08-21
发表期刊	Science
出版年	2020
英文摘要	Unlike graphene and transition-metal dichalcogenides, two-dimensional transition-metal carbides (MXenes) have many surface sites that can be chemically modified. Etching of the aluminum layer of a parent MAX phase Ti3AlC2 layered material with hydrofluoric acid leads to the MXene Ti3C2 with various surface terminations. Molten salts can achieve uniform chloride terminations, but these are difficult to further modify. Kamysbayev et al. show that etching of MAX phases in molten cadmium bromide leads to bromide-terminated MXenes that can then be substituted with oxygen, sulfur, selenium, tellurium, and NH groups as well as with vacancy sites. The surface groups can alter electronic transport. For example, the Nb2C MXenes exhibit surface group–dependent superconductivity. Science , this issue p. [979][1] Versatile chemical transformations of surface functional groups in two-dimensional transition-metal carbides (MXenes) open up a previously unexplored design space for this broad class of functional materials. We introduce a general strategy to install and remove surface groups by performing substitution and elimination reactions in molten inorganic salts. Successful synthesis of MXenes with oxygen, imido, sulfur, chlorine, selenium, bromine, and tellurium surface terminations, as well as bare MXenes (no surface termination), was demonstrated. These MXenes show distinctive structural and electronic properties. For example, the surface groups control interatomic distances in the MXene lattice, and Ti n +1C n ( n = 1, 2) MXenes terminated with telluride (Te2−) ligands show a giant (>18%) in-plane lattice expansion compared with the unstrained titanium carbide lattice. The surface groups also control superconductivity of niobium carbide MXenes. [1]: /lookup/doi/10.1126/science.aba8311
领域	气候变化 ; 资源环境
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文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/291219
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Vladislav Kamysbayev,Alexander S. Filatov,Huicheng Hu,et al. Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes[J]. Science,2020.
APA	Vladislav Kamysbayev.,Alexander S. Filatov.,Huicheng Hu.,Xue Rui.,Francisco Lagunas.,...&Dmitri V. Talapin.(2020).Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes.Science.
MLA	Vladislav Kamysbayev,et al."Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes".Science (2020).