Abstract
Fabricating conductive graphene films by assembling graphene oxide (GO) sheets is highly desired for many applications, however a very high temperature around 3000 K is usually required to repair the sp(2) structure for traditional thermal annealing. Here, an electric field assisted Joule heating method was developed to repair the sp(2) structure in GO at a temperature lower than 1500 degrees C. The resulting free-standing graphene film shows a high electrical conductivity (similar to 1840 S/cm) and high C/O ratio (132), both of which are much higher than those of thermally reduced GO films under the same temperature. These findings provide new possibilities for fabricating high-quality graphene films in an energy-efficient and low-cost manner.