Spiral carbon tubes grown by a mixed-valent oxide-catalytic carbonization process

Abstract

Synthesis of carbon tubes is vitally important in carbon research and applications. In this paper, spiral carbon tubes are grown by a mixed-valent oxide-catalytic carbonization (MVOCC) process. The carbon tubes are highly twisted and have many growth induced nodes. (Fig. 1). The product has high purity and no catalyst particle is found in the product. With the presence of inter-lock structure, the mechanical properties of the material made using the spiral carbon tubes could be significantly improved. The inner tube is not completely hollow but interconnected by graphitic layers. The surfaces of the tubes have many open graphitic edges, thus, a high chemical activity of the tubes is expected. Figure 2 shows a low-magnification TEM image at the initiation side of a carbon tube, where a spiral node is formed. The non-uniform contrast across the node region reflects the spiral geometry at the node.