Switching effective oxygen reduction and evolution performance by controlled graphitization of a cobalt-nitrogen-carbon framework system
Switching effective oxygen reduction and evolution performance by controlled graphitization of a cobalt-nitrogen-carbon framework system
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DOI：
10.1039/c6ee00551a
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发表时间：
2016-01-01
影响因子：
32.5
通讯作者：
Guo, Zhengxiao
中科院分区：
文献类型：
--
作者：
Gadipelli, Srinivas;Zhao, Tingting;Guo, Zhengxiao
我们报告了一个专门设计的路线，用于合成一个有前途的碳基电催化剂的ORR（氧还原反应）和OER（析氧反应）从沸石咪唑骨架（ZIFs）。首先，前体ZIF被合理地设计为具有挥发性锌的共混物以诱导多孔性和稳定的钴以诱导石墨化域。其次，自调制的钴-氮-碳系统（SCNCS）被证明是一个有效的ORR催化剂后，在温和的温度下石墨化。最后，通过提高SCNCS的石墨化程度，开发出最佳的OER催化剂。第一次，仅仅通过切换SCNCS的石墨化条件，就实现了优异的ORR或OER性能。这种方法不仅开辟了一个简单的协议，同时优化的氮掺杂和石墨化在控制钴浓度，但也提供了一种简便的方法，开发这样的活性催化剂，而无需使用大量的合成程序。
We report a purposely designed route for the synthesis of a promising carbon-based electrocatalyst for both ORR (oxygen reduction reaction) and OER (oxygen evolution reaction) from zeolitic imidazolate frameworks (ZIFs). Firstly, precursor ZIFs are rationally designed with a blend of volatile zinc to induce porosity and stable cobalt to induce graphitic domains. Secondly, the self-modulated cobalt-nitrogen-carbon system (SCNCS) is shown to be an effective ORR catalyst after graphitization at mild temperatures. Finally, the best OER catalyst is developed by enhancing graphitization of the SCNCS. For the first time, solely by switching the graphitization conditions of SCNCS, excellent ORR or OER performance is realized. This approach not only opens up a simple protocol for simultaneous optimization of nitrogen doping and graphitization at controlled cobalt concentrations, but also provide a facile method of developing such active catalysts without the use of extensive synthesis procedures.