Preparation of graphene aerogel-poly(3,4-ethylenedioxythiophene) conductive composite by using simultaneous co-vaporized vapor phase polymerization

Abstract

We prepared spherical reduced graphene oxide aerogels (rGOA) through freeze casting and thermal reduction for the fabrication of carbon-conducting polymer composites with excellent electrical and mechanical properties. The rGOA-poly(3,4-ethylenedioxythiophene) (PEDOT) or rGOA-PEDOT-SiO₂ composites were prepared by simultaneous co-vaporized vapor phase polymerization (SC-VPP). The rGOA spherical particles, prepared by freeze casting of GO solution, had a radially oriented pore structure at the center of its cross section and increasing density of GO sheet towards its center because the temperature gradient of the droplet of the GO solution rapidly freezes from the water outside the droplet during the process. The morphology of the rGOA-PEDOT-SiO₂ composites prepared using SCVPP was more spherical compared to rGOA-PEDOT composites, and the orientation of the cross-pore structure was well-developed. Moreover, micrometer-sized conductive PEDOT-SiO₂ hybrid spheres could be formed on the composite’s surface by controlling the amount of FTS oxidant. The rGOA-PEDOT-SiO₂ composites showed lower resistance values and higher current densities at the same voltage than rGOA or rGOA-PEDOT composites. This can be attributed to the surface area of the particle’s surface, which is enlarged due to the presence of the microspheres, which can cause the widening of the contact area with the electrode to facilitate better electron migration.