Facile fabrication of transparent conductive graphene/silica composite films with high mechanical strength

Abstract

A facile method to fabricate transparent conductive composite films of graphene and silica has been proposed, which consists of just mixing a water dispersion of graphene oxide and a neat liquid of tetraethylorthosilicate, followed by thermal reduction under vacuum. The resulting composite films exhibited a high mechanical strength due to a silica network developed in the composites. Transparency of the film was found to depend mostly on the concentration of graphene oxide, but not on silica concentration in the film. The composite films exhibited reasonable electrical conductivities, which were increased by decreasing the amount of silica in the film. It was also found that chemical reduction of graphene oxide by vitamin C, followed by thermal reduction at 800°C, was effective to yield highly conductive and transparent films with excellent mechanical strength.