Vertically aligned MnO2 nanosheets coupled with carbon nanosheets derived from Mn-MOF nanosheets for supercapacitor electrodes
Vertically aligned MnO2 nanosheets coupled with carbon nanosheets derived from Mn-MOF nanosheets for supercapacitor electrodes
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DOI：
10.1007/s10853-018-2562-3
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发表时间：
2018-06
影响因子：
4.5
通讯作者：
Kuangmin Zhao;Ziqin Xu;Zhen He;Guanying Ye;Qingmeng Gan;Zhi Zhou;Suqin Liu
中科院分区：
文献类型：
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作者：
Kuangmin Zhao;Ziqin Xu;Zhen He;Guanying Ye;Qingmeng Gan;Zhi Zhou;Suqin Liu
本文提出了一种在强碱性条件下以Mn-MOF纳米片衍生MnO/CNS为原料，通过低温氧化制备碳纳米片负载MnO2纳米片阵列（MnO2/CNS）的方法。这种从低价锰中获得高价锰的低温方法避免了常规高温合成过程中碳的氧化。制备的MnO2/CNS作为超级电容器电极材料具有优异的电化学性能，在1 M Na2SO4水溶液中，在0.5 a g−1时的最大比电容为339 F g−1。此外，在5 a g−1的电流密度下，MnO2/CNS在5000次充放电循环后的电容保持率为96.1%，表现出超高的稳定性，优于以往报道的大多数MnO2/CNS材料。MnO2/CNS具有优异的容量和循环稳定性，主要是由于其较大的比表面积和原位形成的MnO2纳米片阵列与碳纳米片之间的强耦合。这项工作为mof衍生材料合成高价金属氧化物/碳复合材料提供了一种新的低温方法，用于储能和转换等应用。
A new approach to fabricate carbon nanosheets-supported MnO2 nanosheet arrays (MnO2/CNS) from Mn-MOF nanosheet-derived MnO/CNS through a facile low-temperature oxidation under a strong alkaline condition has been developed. This low-temperature approach to obtain the high-valence Mn species from low-valence Mn species avoids the oxidation of carbon during the conventional high-temperature synthesis. The as-prepared MnO2/CNS exhibits excellent electrochemical performance as an electrode material for supercapacitors with a maximum specific capacitance of 339 F g−1 at 0.5 A g−1 in 1 M Na2SO4 aqueous electrolyte. In addition, the MnO2/CNS displays ultrahigh stability with capacitance retention of 96.1% after 5000 charge–discharge cycles at a current density of 5 A g−1, which is superior than most of the previously reported MnO2/carbon materials. The excellent capacity and cycling stability of MnO2/CNS are mainly due to its large specific surface area and strong coupling between the in situ formed MnO2 nanosheet arrays and carbon nanosheets. This work provides a new low-temperature approach for the synthesis of high-valence metal oxides/carbon composites from MOF-derived materials for the applications such as energy storage and conversion.