Enhanced Reduction of Graphene Oxide on Recyclable Cu Foils to Fabricate Graphene Films with Superior Thermal Conductivity

Large-area freestanding graphene films are facilely fabricated by reducing graphene oxide films on recyclable Cu foils in H2-containing atmosphere at high temperature. Cu might act as efficient catalysts for considerably improved reduction of graphene oxide according to the SEM, EDS, XRD, XPS, Raman and TGA results. Comparing to the graphene films with ~30 μm thickness reduced without Cu substrate at 900 °C, the thermal conductivity and electrical conductivity of graphene films reduced on Cu foils are enhanced about 140% to 902 Wm(-1)K(-1) and 3.6 × 10(4) S/m, respectively. Moreover, the graphene films demonstrate superior thermal conductivity of ~1219 Wm(-1)K(-1) as decreasing the thickness of films to ~10 μm. The graphene films also exhibit excellent mechanical properties and flexibility.