Halloysite nanotubes template-induced fabrication of carbon/manganese dioxide hybrid nanotubes for supercapacitors

Abstract

Carbon/manganese dioxide (C/MnO2) hybrid nanotubes were prepared by the successive deposition of carbon and manganese dioxide using natural halloysite nanotubes as template. The as-prepared hybrids were characterized with transmission electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and Brunauer–Emmett–Teller techniques. The as-prepared C/MnO2 hybrid nanotubes exhibited a well-defined hollow structure with an external diameter of about 200 nm and a specific surface area of 281 m2 g−1. The maximum specific capacitance of the C/MnO2 electrode could reach 239 F g−1 at a current density of 2.5 mA cm−2 in 1 M Na2SO4. In addition, the C/MnO2 electrode showed excellent rate capability and cycle stability, which might be ascribed to the hybridization of carbon and MnO2 and the tubular structure with a high specific surface area.