Fex-Co1-x bimetallic catalysts for highly efficient growth of carbon nanotubes on carbon fibers

This paper aims to develop a catalyst for highly efficient growth of carbon nanotubes (CNTs) on carbon fibers (CFs) with improved tensile strength by chemical vapor deposition (CVD). The effect of the composition of Fe_x-Co_1-x catalysts on the morphology of the synthesized CNTs and the tensile properties of the CFs at different stages of the CVD process were explored. It was found that the bimetallic catalysts possessed better catalytic effect than monometallic catalysts at low temperature. The detailed study of the tensile properties of CFs at different stages of CVD process manifested that the composition of catalysts affected the catalytic activity. When the atomic fraction of Fe was 50%, the bimetallic catalyst among Fe_x-Co_1-x family was considered to hold the highest catalytic efficiency due to the least damage to the fibers and the ability to generate more carbon atoms to repair and reinforce CFs. The corresponding tensile strength of the final CNTs-grafted CFs was 11.53% higher than that of the desized CFs.