Leveling graphene sheets through electrospinning and their conductivity

Abstract

This study provided a strategy to extend and level easily-curved graphene sheets through electrospinning. A suspension of graphene oxide (GO) sheets in polar polymers, such as polyacrylonitrile (PAN) and polyvinyl pyrrolidone (PVP), was first electrospun into a composite network in which the GO sheets were sandwiched and leveled under the drag force of the electrospun nanofibers at the surface and around the edge of the GO sheets. Then, the leveled GO sheets were reduced under the vapor of reducing agents and became graphene sheets. The scanning electron micrographical results confirm the extended and leveled shape of the graphene sheets. With this strategy, the problem of easy curvature of graphene sheets can be thoroughly dissolved. Very importantly, the pressed multilayer samples have a high conductivity of 10³ S m⁻¹. This indicates that wide potential applications of graphene materials from natural graphite in photo- and electro-devices will be developed.