The tunable electrical conductivity of a MWCNT-reduced graphene oxide hybrid film

Graphene oxide (GO) aqueous colloids mixed with different amounts of multi-walled carbon nanotubes (MWCNTs) were dispersed by ultrasonication to form a stable and homogeneous MWCNT-GO suspension. MWCNT-reduced graphene oxide (MWCNT-RGO) hybrid films were obtained by microfiltration, followed by heat treatment at 200℃ for 1h in a vacuum oven to remove most of oxygen-containing functional groups. Results show that the MWCNT-GO hybrid films exhibit a uniformly-layered "sandwich" structure, forming a 3D conductive network. The electrical conductivity of the MWCNT-RGO hybrid films can be tuned by the amount of MWCNTs present and heat treatment conditions. The electrical conductivities of the hybrid films before and after the heat treatment all increase with the MWCNT content. The heat treatment increases the electrical conductivity of the hybrid film with 50% MWCNTs from 1120 to 5380S/m.