Growth of single-crystal α-MnO2 nanorods on multi-walled carbon nanotubes

Single-crystal α-MnO2 nanorods were grown on multi-walled carbon nanotubes (MWNTs) in H2SO4 aqueous solution. The morphology and microstructure of the composites were examined by transmission electron microscopy, high-resolution transmission electron microscopy (HRTEM), X-ray diffractometry and energy dispersive spectroscopy (EDS). The results show that α-MnO2 single-crystal nanorods with a mean diameter of 15 nm were densely grown on the surface of MWNTs. Those MWNTs/MnO2 composites were used as an electrode material for supercapacitors, and it was found that the supercapacitor performance using MWNTs/MnO2 composites was improved largely compared to that using pure MWNTs and α-MnO2 nanorod mechanically mixed with MWNTs.