Study on Bimetallic Catalysts for Carbon Nanotube Growth on the Surface of Continuous Carbon Fibres

We investigated the influence of bimetallic catalysts with various compositions on the growth of carbon nanotubes (CNTs) on the surface of continuous carbon fibers (CFs). The samples were analyzed and characterized by scanning electron microscopy, transmission electron microscopy, and Raman spectrometry. The catalyst plays an essential role in the catalytic chemical vapor deposition of CNT. The performance of these catalysts was estimated referenced to both catalyst and CNT morphologies, while the influences of each catalytic components were summarized according to the results. This work prepared and studied six different bimetallic catalysts composed by Cu, Fe, and Ni, and pure Fe catalyst was employed as a control group. Fe and Ni have been widely studied, while the reports of catalysts containing Cu are rare. We found that pure Fe catalyst leads to banded and clustered CNT distribution, and the addition of Cu can provide uniform and slender CNTs. The efficiency of catalyst can be significantly increased by adding Ni, producing CNTs as well as superfluous amorphous carbon. We determined that bimetallic catalyst can utilize multiple catalytic abilities of various metals by adjusting its composition, which can contribute to obtaining high-quality CNTs on CF surface.