Rational electrodeposition of Cu on highly oxidized multiwalled carbon nanotube films.

Nanohybridization of carbon nanotubes (CNTs) and Cu is a promising strategy to enhance the electrical performance of CNT films or fibers for applications in electromagnetic shielding and for further uses as conductors. However, overcoming the hydrophobic characteristics of CNTs is one of the most appropriate problem faced during the fabrication of hybrid materials with foreign materials. In this study, we report a fabrication method for highly conductive long multiwalled CNTs (LMWCNTs)/Cu hybrid films based on electroplating. The wettability of the Cu plating solution and the electrical conductivity of the LMWCNT films were rationally controlled by thermal deoxygenation in air at temperatures below 200 °C. The thermal modification provides a highly conductive and hydrophilic surface on the CNT structure; these physical changes eventually enable uniform Cu electrodeposition in an aqueous electrolyte. The periodic morphological, electrochemical, electrical, and crystallographic analyses indicate that Cu nucleated from the inside of the CNT film during the initial stage of electrodeposition; further, the Cu nuclei subsequently grew on the CNT surface, resulting in a densely packed CNT-Cu composite. Highly conductive long multiwalled CNTs (LMWCNTs)/Cu hybrid films are fabricated by electroplating, which was rationally controlled by modulating the wettability of the Cu precursor solution on the oxidized LMWCNT films by deoxygenation in air at 150 °C. Image 1 • Thermal deoxygenation alters electrical and surface properties of Ox-LMWCNT for electroplating. • Cu nucleates on the inner and outer surface of the CNT films during electrodeposition. • Cu is electroplated uniformly with high electrical conductivity through the CNT film. • CNT-Cu is nanohybridized by electrodeposition in an aqueous system. [ABSTRACT FROM AUTHOR]