Effects of Graphene Oxide and Reduced Graphene Oxide Interlayer Interactions on the Charge Storage Mechanism

Graphene (GP) has been an object of great interest for researchers ever since its isolation from graphite back in 2004. A great many details about the electronic structure and properties of GP has been extensively studied and the knowledge gained has been utilized in fabricating a wide variety of devices. However, to the best of authors knowledge, there has never been a report studying the interlayer interaction (ILI) properties of graphene oxide (GO)/reduced graphene oxide (rGO) composite. Here, we report fabricating GO_GO, GO_rGO, rGO_rGO, and rGO_GO electrodes through screen printing and study their electronic structure and properties through spectroscopic and electroanalytical methods. The electroanalytical techniques used were cyclic voltammetry, Tafel analysis. electrochemical impedance spectroscopy, chronoamperometry, and galvanostatic charging and discharging (GCD). Standard K3[Fe(CN)6] solution of 1 mM concentration was used in investigating the ILI properties. Furthermore, the electrochemical double layer charge storage (EDLC) mechanism for all the systems were investigated through two electrode symmetrical and asymmetrical setups. Though the research is just in its infancy, analysis of the data obtained so far shows the areal capacitance for the symmetric GO_GO, GO_rGO, rGO_rGO, and rGO_GO systems to be 0.74, 3.24, 0.22, and 0.31 mF/cm2, respectively in 1M KCl aqueous solution. For the asymmetrical system the GO_rGO(anode)-GO_GO(cathode) (4.92 mF/cm2) setup showed the highest areal specific capacitance. The operating potential window optimization revealed that GO_rGO and GO_rGO(anode)-GO_GO(cathode) setups could maintain EDLC up to 1V window, while the other setups started showing deviations after 0.7 V window. We intend to thoroughly investigate the ILI process for these four different setups and how they contribute to the EDLC mechanism.