In situ assembly of MnO₂ nanowires/graphene oxide nanosheets composite with high specific capacitance

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• 作者：Kai Dai ; Luhua Lu ; Changhao Liang ; Jianming Dai ; Qinzhuang Liu ; Yongxing Zhang ; Guangping Zhu ; Zhongliang Liu
• 关键词：Graphene oxide ; MnO2 ; Hybrid ; Supercapacitors ; Electrochemical capacitance
• 刊名：Electrochimica Acta
• 出版年：10 January, 2014
• 年：2014
• 卷：116
• 期：Complete
• 页码：111-117
• 全文大小：2613 K

文摘

Graphene oxide (GO) in situ composited with MnO₂ nanowires was achieved through a hydrothermal process. The morphology and structure of the products were investigated by using field emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectra and X-ray diffraction. The results showed that the product consisted of 伪-MnO₂ nanowires with the diameter of 20鈭?0 nm and the length of 0.5鈭? 渭m that well dispersed on the surfaces of GO. The excellent electrochemical performance of as-prepared GO/MnO₂ hybrids was obtained due to the unique chemical interactions between GO and MnO₂. The maximum specific capacitances of 360.3 F/g measured by chronopotentiometry at a current density of 0.5 A/g were obtained in a 1 M Na₂SO₄ aqueous solution. This value is much higher than that of pure MnO₂ nanowire electrodes (128.0 F/g) and commercial MnO₂ microparticles electrodes (22.8 F/g). Furthermore, GO/MnO₂ nanowires hybrids also exhibit good cycling stability with more than 93% capacitance retention over 1000 cycles. The present synthesis strategy may be readily extended to the preparation of other hybrids based on GO nanosheets for potential applications in energy storage and conversion devices.