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

• DOI: 10.1016/j.electacta.2013.11.036
• Publication Date: 2013-11-21T07:21:14Z
• Authors: Kai Dai; Luhua Lu; Changhao Liang; Jianming Dai; Qinzhuang Liu; Yongxing Zhang; Guangping Zhu; Zhongliang Liu
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

Abstract Graphene oxide (GO) in situ composited with MnO 2 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 α-MnO 2 nanowires with the diameter of 20∼40 nm and the length of 0.5∼2 μm that well dispersed on the surfaces of GO. The excellent electrochemical performance of as-prepared GO/MnO 2 hybrids was obtained due to the unique chemical interactions between GO and MnO 2 . 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 Na 2 SO 4 aqueous solution. This value is much higher than that of pure MnO 2 nanowire electrodes (128.0 F/g) and commercial MnO 2 microparticles electrodes (22.8 F/g). Furthermore, GO/MnO 2 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.