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International Journal of Electrochemistry
Volume 2012 (2012), Article ID 475417, 10 pages
http://dx.doi.org/10.1155/2012/475417
Research Article

Spontaneous Synthesis and Electrochemical Characterization of Nanostructured on Nitrogen-Incorporated Carbon Nanotubes

1Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan
2Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
3Department of Opto-Electronic Engineering, National Dong Hwa University, Hualien 97401, Taiwan
4Institute of Atomic and Molecular Science, Academia Sinica, Taipei 106, Taiwan

Received 2 September 2011; Accepted 11 October 2011

Academic Editor: V. S. Reddy Channu

Copyright © 2012 Ying-Chu Chen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper investigated the layered manganese dioxide with hydrate () deposits onto nitrogen-containing carbon nanotube (CNxNTs) as a hierarchical electrode for an energy-storage device. The dense and entangled CNxNTs were directly grown by microwave plasma-enhanced chemical vapor deposition (MPECVD) on a carbon cloth (CC), and subsequently used as a current collector. By controlling the pH value of KMnO4 precursor solution, and incorporating nitrogen into CNTs as a reducing agent, the MnO2 thin layer was uniformly fabricated on the CNxNTs at room temperature by using a spontaneous reduction method. The role of incorporation nitrogen is not only capable of creating active sites on the CNT surface, but can also donate electrons to reduce to MnO2 spontaneously. From the measurements of cyclic voltammograms and galvanostatic charge/discharge, MnO2/CNxNTs/CC composite electrodes illustrated excellent specific capacitance of 589.1 Fg−1. The key factor for high performance could be attributed to the thin-layered MnO2 nanostructure, which resulted in the full utilization of MnO2 deposits. Hence, the hierarchically porous MnO2/CNxNTs/CC electrodes exhibited excellent capacitive behavior for electrochemical capacitor application.