Oxidation-Etching Preparation
of MnO<sub>2</sub> Tubular
Nanostructures for High-Performance Supercapacitors
- Publication date
- Publisher
Abstract
1D hierarchical tubular MnO<sub>2</sub> nanostructures
have been
prepared through a facile hydrothermal method using carbon nanofibres
(CNFs) as sacrificial template. The morphology of MnO<sub>2</sub> nanostructures
can be adjusted by changing the reaction time or annealing process.
Polycrystalline MnO<sub>2</sub> nanotubes are formed with a short
reaction time (e.g., 10 min) while hierarchical tubular MnO<sub>2</sub> nanostructures composed of assembled nanosheets are obtained at
longer reaction times (>45 min). The polycrystalline MnO<sub>2</sub> nanotubes can be further converted to porous nanobelts and sponge-like
nanowires by annealing in air. Among all the types of MnO<sub>2</sub> nanostructures prepared, tubular MnO<sub>2</sub> nanostructures
composed of assembled nanosheets show optimized charge storage performance
when tested as supercapacitor electrodes, for example, delivering
an power density of 13.33 kW·kg<sup>–1</sup> and a energy
density of 21.1 Wh·kg<sup>–1</sup> with a long cycling
life over 3000 cycles, which is mainly related to their features of
large specific surface area and optimized charge transfer pathway