Strongly coupled MoS2 nanoflake-carbon nanotube nanocomposite as an excellent electrocatalyst for hydrogen evolution reaction
Strongly coupled MoS2 nanoflake-carbon nanotube nanocomposite as an excellent electrocatalyst for hydrogen evolution reaction
复制标题
强耦合MoS2纳米片-碳纳米管纳米复合材料作为析氢反应的优异电催化剂
DOI：
10.1039/c6ta09612c
复制
发表时间：
2017-01-28
影响因子：
11.9
通讯作者：
Liu, Yingju
中科院分区：
文献类型：
--
作者：
Huang, Haoliang;Huang, Weihao;Liu, Yingju
MoS_2是一种很有前途的非贵金属析氢电催化剂，但存在电导受阻和活性中心稀少的问题。这种棘手的情况可以得到改善，但不能通过简单的纳米碳化物的参与来消除。本文合成了一种树枝状的强耦合多孔MoS_2-碳纳米管(CNT)纳米复合材料，其中几层MoS_2纳米片径向紧密地锚定在碳纳米管的表面。Mo-O-C被认为是这两个相之间的桥梁，并提出了强耦合MoS_2-CNT界面的三明治结构。这种真正的纳米复合材料对HER表现出显著的电催化活性，达到-850 mA cm(Geo)(-2)，而过电位仅为290 mV，即使在100 mA cm(Geo)(-2)的电流密度下，也保持了每十年47 mV的低Tafel斜率。经过详细分析，这种激增的活性与其说是由于MoS_2和CNT性质的简单增加，不如说是因为它们之间强烈的界面结合，这种结合不仅稳定了微小的、边缘端接的MoS_2纳米片，而且构建了三维分级结构，促进了HER操作过程中的电子和质量传递。
As a promising non-precious metal electrocatalyst for the hydrogen evolution reaction (HER), MoS2 suffers from impeded electrical conductivity and scarce active sites. This tricky situation can be ameliorated but not eliminated by the simple involvement of nanocarbons. Herein, a leaves-and-branch structure of strongly coupled and porous MoS2-carbon nanotube (CNT) nanocomposite was synthesized, where few-layer MoS2 nanoflakes are anchored radially and intimately on the surface of CNT. Mo-O-C has been unveiled to be the bridge between these two phases and a sandwich-like structure was proposed for the interface within the strongly coupled MoS2-CNT. This genuine nanocomposite exhibits remarkably improved electrocatalytic activity towards HER, reaching -850 mA cm(geo)(-2) with the expense of only 290 mV of overpotential and maintaining a low Tafel slope of 47 mV per decade even under a current density of 100 mA cm(geo)(-2). After detailed analysis, this surging activity has been ascribed not so much to the simple addition of the properties of MoS2 and CNT, but to a strong interfacial attachment between them which not only stabilizes tiny and edge-terminated MoS2 nanoflakes, but also constructs a three dimensional hierarchical structure to boost electron and mass transfer during the HER operation.