Synthesis of vertically aligned carbon nanotubes on carbon fiber

► Vertically aligned carbon nanotubes were synthesized on the surface of carbon fiber. ► Compact and adhesive coating of catalyst on carbon fiber was achieved without the application of additional pre-deposited substrate. ► Acid treatment, ultrasonic assisted catalyst-dip coating and calcination were the main steps, which provided appropriate catalyst coating. ► Two types of solvent, acetone and ethanol, were examined in dip coating step and acetone was found more effective to produce dense catalyst coating.