Producing large-area, foldable graphene paper from graphite oxide suspensions by in-situ chemical reduction process

Abstract

Graphene paper has attracted considerable attention because of its impressive electrical and mechanical properties, which endow it with the great potential for applications in future flexible electronics. Therefore, developing a high-efficiency route to fabricate large-area and foldable graphene paper with good electrical and mechanical properties is quite necessary. In this work, a facile in-situ chemical reduction method for the preparation of graphene paper was successfully developed. The in-situ chemical reduction process involves simultaneous film formation and reduction, and the produced graphene paper has high integrity and good foldability. The thickness and area of graphene paper can also be readily regulated by adjusting the experimental parameters. Furthermore, the dissipation of reductant air stream (HI/CH3COOH air stream) can “push up” the graphene nanosheets to form a loose layered structure. This inside-out reduction process gives the produced graphene paper a sheet resistance as low as 17.8 Ω sq−1, verifying the advantages of this in-situ chemical reduction method. For the application of the obtained graphene paper, a flexible solid-state supercapacitor based on the graphene paper was fabricated, which had a device areal capacitance of 44 mF cm−2 (device volumetric capacitance of 858 mF cm−3) and excellent electrochemical stability.