Fast, scalable, and environmentally friendly method for production of stand-alone ultrathin reduced graphene oxide paper

In the present, there is a big need for materials that can replace materials currently used in technologies, improving mainly the performance and ecological impact of manufacturing. Graphene-based materials are such an alternative, primarily graphene oxide (GO) and reduced graphene oxide (rGO). This work presents a scalable, fast, safe, and eco-friendly method for preparing rGO thin paper (similar to 5 mu m) with conductivity reaching 435 S/m. These rGO papers were fabricated by reducing thin GO paper prepared in an in-house-built vacuum chamber and applying spraying cycles of GO dispersion for a precise and highly controllable deposition process. The atmospheric plasma generated by Diffuse Coplanar Surface Barrier Discharge (DCSBD) plasma source was employed for rapid GO reduction-exfoliation (in the order of seconds) to prepare highly porous rGO paper. Prepared rGO papers were then post-processed by a cold rolling press into uniform conductive self-standing pure rGO papers to create more precisely defined samples and enhance their mechanical and electrical properties. The morphology of GO and rGO papers was studied by SEM and AFM, the chemical changes before/after the plasma reduction were analyzed by the XPS technique and the electrical parameters of the fabricated papers were analyzed by the 4-point probe method and the structure of GO and rGO was analyzed by Raman and XRD methods. The short duration and the scalability potential of the herein-described plasma-reduction-exfoliation method open new possibilities for large-scale implementation of rGO papers in industrial applications.