Enhanced thermal conductivity of free-standing 3D hierarchical carbon nanotube-graphene hybrid paper

Light-weight materials with superior thermal and electrical transport properties have received much attention for effective thermal management. In this study, we develop a three-dimensional (3D) hybrid hierarchical structure with carbon nanotube (CNT) intercalated graphene sheets by thermal annealing of carbon nanotube/graphene oxide (CNT/GO) films. In this full-carbon architecture, CNTs are employed to bridge adjacent graphene sheets to facilitate the phonon propagation and prevent the corrugation of graphene layers during thermal treatment. The as-obtained carbon nanotube/graphene (CNT/G) film with 15 wt% CNTs content exhibits ultrahigh in-plane thermal conductivity of 1388.7 W/mK and favorable electric conductivity of 1.7 × 105 S/m. The mechanisms of the enhanced thermal conductivities of the hybrid films are then analyzed by theoretical simulation. These films could be useful in thermal management for next generation commercial portable electronics.