Direct growth of flexible carbon nanotube electrodes

The growth of carbon nanotube networks integrated into a carbon layer (CL) on insulating graphitic carbon and on metallic substrates by modifying the CVD synthesis was investigated. A thin film of iron(III) p-toluenesulfonate (Fe(III)pTS) catalyst was spin-coated onto quartz plates from organic solutions. The resultant CNT films were observed to be very much unlike to those grown using conventional catalyst. The CNT/CL paper was characterized using a range of methods. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed the top layer indeed consisted of CNTs, whilst SEM of the cross-sectional area revealed a highly porous 3D structured CNT network grown on top of a dense CL with less than 1 μm thickness. The Fe content of the CL layer was measured to be <5% using energy dispersive X-ray analysis and thermogravimetric analysis. It was observed that the the CNT/CL paper electrodes are lightweight, flexible, and highly conductive.