Li Yang, Zhang Rupeng, Zhou Wei, Wu Xin, Zhang Huabin, Zhang Jian
State Key Laboratory of Structural Chemistry , Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou 350002 , China.
College of Chemistry , Fuzhou University , Fuzhou 350108 , China.
ACS Nano. 2019 May 28;13(5):5533-5540. doi: 10.1021/acsnano.9b00383. Epub 2019 Apr 22.
Achieving a molecular level understanding of surface performance of nanomaterials by modulating the electronic structure is important but challenging. Here, we have developed a hollow microcube framework constructed by Mo-defect-rich ultrathin MoS nanosheets (HMF-MoS) through a zeolite-like-framework-engaged strategy. The hollow structured HMF-MoS delivers an impressive specific capacity (384.3 mA h g after 100 cycles at 100 mA g) and cycle stability (267 mA h g after 125 cycles at 1 A g) for sodium storage. As evidenced by experiments and density functional theory calculations, abundant Mo vacancies in MoS can greatly accelerate the charge transfer and enhance the interaction between MoS and sodium, resulting in the promotion of sodium storage. Kinetic analysis result reveals that the ultrafast sodium ion storage of HMF-MoS could be associated with the significant contribution of capacitive energy storage. This work highlights the detailed molecular level understanding of chemical reaction on MoS surface by defect and morphology engineering, which can be applied to other metal sulfides for energy storage devices.
通过调节电子结构来实现对纳米材料表面性能的分子水平理解很重要，但具有挑战性。在此，我们通过一种类沸石框架参与策略，开发了一种由富含钼缺陷的超薄MoS纳米片构建的中空微立方框架（HMF-MoS）。这种中空结构的HMF-MoS在储钠方面展现出令人印象深刻的比容量（在100 mA g下循环100次后为384.3 mA h g）和循环稳定性（在1 A g下循环125次后为267 mA h g）。实验和密度泛函理论计算表明，MoS中大量的钼空位可极大地加速电荷转移并增强MoS与钠之间的相互作用，从而促进储钠。动力学分析结果表明，HMF-MoS的超快钠离子存储可能与电容储能的显著贡献有关。这项工作突出了通过缺陷和形貌工程对MoS表面化学反应进行详细的分子水平理解，这可应用于其他用于储能器件的金属硫化物。
