Synthesis of aligned carbon nanotube composite fibers with high performances by electrochemical deposition

To improve their practical applications, carbon nanotubes (CNTs) have recently been assembled into macroscopic fibers in which the CNTs are aligned to maintain their excellent properties. To further enhance the properties and expand the application of CNT fibers, it is critically important to introduce a second functional phase to produce high performance composite fibers. Herein, a general and efficient electrodeposition method has been developed to synthesize aligned CNT composite fibers into which a wide variety of components including metals and conductive polymers can be incorporated. The resulting composite fibers show remarkable mechanical and electrical properties, which enable promising applications in various fields. As a demonstration, CNT/silver composite fibers exhibit a high signal enhancement under weak laser irradiation when used as wire substrates for surface enhanced Raman scattering, and CNT/polyaniline composite fibers have been used to fabricate wire-shaped supercapacitors which achieve a specific capacitance of 2.26 mF cm^-1, at least two orders of magnitude greater than that of bare CNT fibers, and ten times that of other fiber materials, such as plastic wires coated with zinc oxide nanowires.