Partic. vol. 15 pp. 34-38 (August 2014)
doi: 10.1016/j.partic.2012.12.006

acile synthesis and electrochemical properties of MnO₂/carbon nanotubes

Yang Lv^a,b, Huanqiao Li^b, Yan Xie^b, Shushuang Li^b, Jia Li^b,c, Yongheng Xing^a,*, Yujiang Song^b

yhxing2000@yahoo.com

Abstract

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 MnO2 nanosheets with a thickness 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.

Graphical abstract

Keywords

MnO₂; MWCNTs-OH; Supercapacitor; Non-noble metal electrocatalyst