Quantum Dots of 1T Phase Transitional Metal Dichalcogenides Generated via Electrochemical Li Intercalation
Quantum Dots of 1T Phase Transitional Metal Dichalcogenides Generated via Electrochemical Li Intercalation
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通过电化学锂嵌入生成 1T 相过渡金属二硫属化物的量子点
DOI：
10.1021/acsnano.7b06364
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发表时间：
2018-01-01
期刊：
影响因子：
17.1
通讯作者：
Zhang, Di
中科院分区：
文献类型：
--
作者：
Chen, Wenshu;Gu, Jiajun;Zhang, Di
我们通过准全电化学方法从具有量子尺寸和单层特征的1 T相制备了第VI族过渡金属二硫属化物（TMD，或MX 2）。得到的二维（2D）MX2（M = W，Mo; X = S，Se）量子点（QD）约为100 μ m。尺寸为3.0-5.4轮辋，具有约3.0-5.4轮辋的高IT相分数。92%-97%。我们将其归因于插入1 T-MX2晶格中的高Li含量（Li：M的摩尔比超过2：1），这是通过增加的锂化驱动力和降低的电化学锂化速率（0.001 A/g）实现的。高Li含量不仅促进2 H-> 1 T相变，而且产生显著的内应力，促进MX 2晶体的晶格断裂。由于其高比例的金属IT相和由小的横向尺寸诱导的足够的活性位点，2D 1 T-MoS 2 QD显示出优异的析氢反应性（具有92 mV的典型eta（10），44 mV/dec的Tafel斜率，和4.16 x 10（-4）A/cm（2）的J（0））。这种通往2D量子点的电化学途径可能有助于推动能源相关领域2D材料的发展。
We prepare group VI transitional metal dichalcogenides (TMDs, or MX2) from the 1T phase with quantum-sized and monolayer features via a quasi-full electrochemical process. The resulting two-dimensional (2D) MX2 (M = W, Mo; X = S, Se) quantum dots (QDs) are ca. 3.0-5.4 rim in size with a high IT phase fraction of ca. 92%-97%. We attribute this to the high Li content intercalated in the 1T-MX2 lattice (mole ratio of Li:M is over 2:1), which is achieved by an increased lithiation driving force and a reduced electrochemical lithiation rate (0.001 A/g). The high Li content not only promotes the 2H -> 1T phase transition but also generates significant inner stress that facilitates lattice breaking for MX2 crystals. Because of their high proportion of metallic IT phase and sufficient active sites induced by the small lateral size, the 2D 1T-MoS2 QDs show excellent hydrogen evolution reactivity (with a typical eta(10) of 92 mV, Tafel slope of 44 mV/dec, and J(0) of 4.16 x 10(-4) A/cm(2)). This electrochemical route toward 2D QDs might help boost the development of 2D materials in energy-related areas.