Graphene aerogels: part 2 - derived from commercial graphene and chemically reduced graphene oxide via supercritical carbon dioxide drying

Abstract

Graphene aerogels (GAs), the most important class of carbonaceous aerogels, have attracted attention of many researchers due to their superior physical and chemical properties. In this study, commercial graphene (GR) and chemically reduced graphene oxide (RGO) were used as graphene-based precursor materials, unlike graphene oxide (GO), which is widely used in the literature in GA synthesis. GAs were synthesized using the sol-gel technique and dried with supercritical carbon dioxide (SCCO2). In addition, graphene-based materials were used in different ratios and their distribution in the aerogel matrix and its effect on surface properties were investigated. In addition, the synthesized GAs were structurally compared with GR, RGO, and carbon aerogel (CA) without graphene-based materials. Physical characterizations (Brunauer, Emmett, and Teller (BET) analysis, scanning electron microscope-energy dispersive X-ray (SEM-EDX) analysis, micro-Raman spectroscopy, X-ray diffractometer (XRD) were made to examine the structural properties of GAs. In order to analyze the behavior of the surfaces of the synthesized materials against electrochemical corrosion, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses were performed. As a result of the electrochemical corrosion process of the synthesized materials, the change in their specific capacitance and the formation of pseudocapacitive charge on the surfaces were examined.