• 文献标题:   Assembling Hollow Cobalt Sulfide Nanocages Array on Graphene-like Manganese Dioxide Nanosheets for Superior Electrochemical Capacitors
  • 文献类型:   Article
  • 作  者:   CHEN H, WANG MQ, YU YN, LIU H, LU SY, BAO SJ, XU MW
  • 作者关键词:   metalorganic framework, manganese dioxide nanosheet, cobalt sulfide, hollow nanocages array, electrochemical capacitor
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244 EI 1944-8252
  • 通讯作者地址:   Southwest Univ
  • 被引频次:   30
  • DOI:   10.1021/acsami.7b12069
  • 出版年:   2017

▎ 摘  要

Metal-organic framework (MOF)-derived hollow cobalt sulfides have attracted extensive attention due to their porous shell that provides rich redox reactions for energy storage. However, their ultradispersed structure and the large size of MOF precursors result in relatively low conductivity, stability, and tap density. Therefore, the construction of an array of continuous hollow cages and tailoring of the inner cavity of MOF-derived materials is very effective for enhancing the electrochemical performance. Herein, we in situ assembled small Co-based zeolitic imidazolate framework (ZIF-67) on the both sides of negatively charged MnO2 nanosheets to fabricate a hierarchical sandwich-type composite with hollow cobalt sulfide nanocages/graphene-like MnO2. The graphene-like MnO2 nanosheets acted not only as a structure-directing agent to grow a ZIF-67 array but also as a promising electroactive material of electrochemical capacitors to provide capacitance. As electrode material of supercapacitors, the as-prepared composites exhibit high specific capacitance (1635 F g(-1) at 1 A g(-1)), great rate performance (reaching 1160 F g(-1) at 10 A g(-1)), and excellent cycling stability (80% retention after 5000 cycles). The outstanding electrochemical properties of our designed materials can be attributed to the unique nanostructure that improved electrical conductivity, created more reactive active sites, and increased the diffusion pathway for electrolyte ions.