School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
Angew Chem Int Ed Engl. 2017 Jun 12;56(25):7141-7145. doi: 10.1002/anie.201702649. Epub 2017 May 16.
Complex metal-organic frameworks used as precursors allow design and construction of various nanostructured functional materials which might not be accessible by other methods. Here, we develop a sequential chemical etching and sulfurization strategy to prepare well-defined double-shelled zinc-cobalt sulfide (Zn-Co-S) rhombic dodecahedral cages (RDCs). Yolk-shelled zinc/cobalt-based zeolitic imidazolate framework (Zn/Co-ZIF) RDCs are first synthesized by a controlled chemical etching process, followed by a hydrothermal sulfurization reaction to prepare double-shelled Zn-Co-S RDCs. Moreover, the strategy reported in this work enables easy control of the Zn/Co molar ratio in the obtained double-shelled Zn-Co-S RDCs. Owing to the structural and compositional benefits, the obtained double-shelled Zn-Co-S RDCs exhibit enhanced performance with high specific capacitance (1266 F g at 1 A g ), good rate capability and long-term cycling stability (91 % retention over 10,000 cycles) as a battery-type electrode material for hybrid supercapacitors.
采用复杂的金属-有机骨架作为前体制备各种纳米结构功能材料，这是其他方法所无法实现的。在这里，我们开发了一种顺序化学刻蚀和硫化策略，用于制备具有良好定义的双层锌-钴硫化物（Zn-Co-S）菱形十二面体笼（RDC）。首先通过控制化学刻蚀过程合成具有核壳结构的锌/钴基沸石咪唑骨架（Zn/Co-ZIF）RDC，然后通过水热硫化反应制备双层 Zn-Co-S RDC。此外，本工作中报道的策略可以方便地控制所得双层 Zn-Co-S RDC 中的 Zn/Co 摩尔比。由于结构和组成上的优势，所得双层 Zn-Co-S RDC 作为混合超级电容器的电池型电极材料表现出增强的性能，具有高比电容（在 1 A g 时为 1266 F g ）、良好的倍率性能和长循环稳定性（在 10000 次循环后保持 91%）。
