Synthesis and Characterization of 2D Molybdenum Carbide (MXene)
Synthesis and Characterization of 2D Molybdenum Carbide (MXene)
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DOI：
10.1002/adfm.201505328
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发表时间：
2016-05-10
影响因子：
19
通讯作者：
Barsoum, Michel W.
中科院分区：
文献类型：
--
作者：
Halim, Joseph;Kota, Sankalp;Barsoum, Michel W.
大规模的合成和分层的2D Mo 2CTx（其中T是一个表面终止基团）已经实现了选择性蚀刻镓从最近发现的纳米层压，三元过渡金属碳化物Mo 2Ga 2C。不同的合成和分层路线导致不同的片状形貌。自支撑的Mo 2CTx膜的电阻率增加了一个数量级的温度从300至10 K降低，这表明该MXene的类似超导体的行为，与Ti 3C 2 Tx，表现出金属的行为。在10 K时，磁阻为正。此外，电子输运的变化，观察退火后的薄膜。当2 μ m厚的膜作为超级电容器的电极进行测试时，在1 M硫酸电解质中获得高达700 F cm（-3）的电容和在10 A g（-1）下至少10，000次循环的高容量保持率。具有约8wt%碳纳米管的独立式Mo 2CTx膜在作为Li离子的电极材料测试时表现良好，特别是在高速率下。在20和131 C循环速率下，超过1000次循环分别实现250和76 mAh g（-1）的稳定可逆容量。
Large scale synthesis and delamination of 2D Mo2CTx (where T is a surface termination group) has been achieved by selectively etching gallium from the recently discovered nanolaminated, ternary transition metal carbide Mo2Ga2C. Different synthesis and delamination routes result in different flake morphologies. The resistivity of free-standing Mo2CTx films increases by an order of magnitude as the temperature is reduced from 300 to 10 K, suggesting semiconductor-like behavior of this MXene, in contrast to Ti3C2Tx which exhibits metallic behavior. At 10 K, the magnetoresistance is positive. Additionally, changes in electronic transport are observed upon annealing of the films. When 2 mu m thick films are tested as electrodes in supercapacitors, capacitances as high as 700 F cm(-3) in a 1 M sulfuric acid electrolyte and high capacity retention for at least 10,000 cycles at 10 A g(-1) are obtained. Free-standing Mo2CTx films, with approximate to 8 wt% carbon nanotubes, perform well when tested as an electrode material for Li-ions, especially at high rates. At 20 and 131 C cycling rates, stable reversible capacities of 250 and 76 mAh g(-1), respectively, are achieved for over 1000 cycles.