Hierarchical architecture of WS2 nanosheets on graphene frameworks with enhanced electrochemical properties for lithium storage and hydrogen evolution
Hierarchical architecture of WS2 nanosheets on graphene frameworks with enhanced electrochemical properties for lithium storage and hydrogen evolution
复制标题
石墨烯框架上的 WS2 纳米片的分层结构具有增强的锂存储和析氢电化学性能
DOI：
10.1039/c5ta06840a
复制
发表时间：
2015-01-01
影响因子：
11.9
通讯作者：
Xu, Mingsheng
中科院分区：
文献类型：
--
作者：
Huang, Guowei;Liu, Hao;Xu, Mingsheng
首次采用水热法制备了以三维石墨烯（3DG）为骨架的层状WS 2纳米片。3DG框架可以为组装WS 2纳米片提供大的表面积和用于快速电子转移和离子传输的连续路径;并且由于氧的掺入，具有9.58 A的扩展层间距的WS 2纳米片可以提供更多的锂离子嵌入空间和更多的析氢活性位点。所制备的WS 2/3DG复合材料表现出766 mA h g−1的高容量和优异的锂储存循环稳定性，远优于其退火对应物和块状WS 2。WS 2/3DG的水合片层还表现出对于析氢反应的增强的电催化活性，具有75 mV的低起始过电位和在300 mV下137 mA cm-2的极大电流密度，具有显著的耐久性。这一工作可能为通过协同优化电极结构和活性材料的固有电活性来改善电化学性能开辟了新的途径。
Hierarchical architecture of ultrathin interlayer-expanded WS2 nanosheets supported on three-dimensional graphene (3DG) frameworks is fabricated by a facile hydrothermal method for the first time. The 3DG frameworks could provide large surface area for assembling WS2 nanosheets and continuous pathways for rapid electron transfer and ion transport; and the WS2 nanosheets with an expanded interlayer spacing of 9.58 A, due to oxygen incorporation, could afford more space for lithium ion intercalation and more active sites for hydrogen evolution. The as-prepared WS2/3DG composite exhibits a high capacity of 766 mA h g−1 and excellent cycling stability for lithium storage, much better than its annealed counterpart and bulk WS2. The hydrated sheet of WS2/3DG also demonstrates boosted electrocatalytic activity for the hydrogen evolution reaction, possessing a low onset overpotential of 75 mV and an extremely large current density of 137 mA cm−2 at 300 mV with remarkable durability. This work may open up a new pathway for improving the electrochemical properties by synergistically optimizing the electrode architectures and the intrinsic electroactivity of the active materials.