The poor electrical conductivity of MnO2 limits its use as an electrode material. To overcome this limitation, we report an easy and rapid approach to deposit nanosized MnO2 onto multi-wall carbon nanotubes functionalized with hydroxyl groups （MWCNTs-OH） by chemical reduction of KMnO4 with MnSO4 in aqueous solution under ambient conditions. Characterization with XRD and TEM reveals that the obtained MnO2/MWCNTs-OH composite is nanocrystalline and partially covered by Mn02 nanosheets with a thick- ness of 1-3 nm at a MnO2 loading of 20 wt%. Cyclic voltammetry （CV） and galvanostatic charge-discharge measurements reveal that the MnO2/MWCNTs-OH composite with a MnO2 loading of 20 wt% has a relatively high specific capacitance of 234 F/g at a scan rate of 2 mV/s and exhibits good cycling stability. Furthermore, the oxygen reduction reaction （ORR） shows that MnO2/MWCNTs-OH composite may have potential applications as a non-noble metal electrocatalyst in fuel cells and metal-air batteries.
Yang LvHuanqiao LiYan XieShushuang LiJia LiYongheng XingYujiang Song
