Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes
Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes
复制标题
DOI：
10.1126/science.aba8311
复制
发表时间：
2020-08-21
期刊：
影响因子：
56.9
通讯作者：
Talapin, Dmitri, V
中科院分区：
文献类型：
--
作者：
Kamysbayev, Vladislav;Filatov, Alexander S.;Talapin, Dmitri, V
二维过渡金属碳化物（MXenes）表面官能团的多种化学转化为这类广泛的功能材料开辟了一个以前未开发的设计空间。我们介绍了一种通过在熔融无机盐中进行取代和消除反应来安装和去除表面基团的一般策略。成功地合成了氧、亚胺、硫、氯、硒、溴和碲表面末端的MXenes，以及裸MXenes（无表面末端）。这些MXenes显示出独特的结构和电子特性。例如，表面基团控制了MXene晶格中的原子间距离，并且与未应变的碳化钛晶格相比，以碲化物（Te2-）配体端接的Tn+1Cn (n = 1,2) MXenes显示出巨大的（>18%）面内晶格膨胀。表面基团还控制着碳化铌MXenes的超导性。
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 Tn+1Cn (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.