Stand-up structure of graphene-like carbon nanowalls on CNT directly grown on polyacrylonitrile-based carbon fiber paper as supercapacitor

This work demonstrates the directly grown graphene-like carbon nanowall (GNW)-carbon nanotube (CNT)polyacrylonitrile-based carbon fiber (CF) paper structure for use as a highly efficient supercapacitor. The CF was prepared by electrospinning. and was then treated by carbonization. The CNTs were directly grown on the CF paper by microwave plasma-enhanced chemical vapor deposition using CH4/H-2 precursors at 800 degrees C. The GNW was further reconstructed onto the CNT surface by microwave plasma-enhanced chemical vapor deposition using CH4/H-2 precursors at 1500 degrees C (GNW-CNT/CF). Electrochemical measurements demonstrate that the capacitance of the GNW-CNT/CF electrode is around 176 F g(-1) at a charging/discharging current density of 0.5 mA/cm(2). The stand-up structure of GNW-CNT/CF has a high capacitance, attributable to its large surface area, high electrical conductivity and direct growth with low energy-loss. This novel stand-up structure of GNW-CNT/CF with a high surface area and low electron-transfer resistance has great potential for developing a revolutionary new class of nanostructured electrodes in supercapacitors or other energy-conversion applications. (C) 2012 Elsevier B.V. All rights reserved.