Electrolyte dependent performance of graphene–mixed metal oxide composites for enhanced supercapacitor applications

Abstract

Graphene-metal frameworks have been extensively studied and developed as electrode materials for next generation energy storage materials. Their high surface area and easily transformable structure enhances its specific capacitance characteristics. In the present study, graphene oxide (GO) was synthesized using Hummers method. Zinc oxide and copper oxide nanoparticles were incorporated in to the GO matrix to form mixed metal oxides. GO, GO-CuO and GO-ZnO were characterized using UV-Visible, FTIR, FT Raman spectroscopy, SEM and XRD to confirm their effective formation. The surface of the glassy carbon electrode was modified by drop casting with the samples on its surface and its electrochemical properties were studied. Cyclic Voltammetry studies were conducted at various scan rates in different electrolytes (KCl, H 2 SO 4 and Na 2 SO 4) and the characteristic curves were observed to be asymmetric in nature. GO-CuO exhibits the highest specific capacitance of 790 F/g at 5 mV/s in KCl. The specific capacitance of the modified electrodes was also measured using the Chronopotentiometry technique. GO-CuO nanocomposites show a maximum specific capacitance of 800 F/g at 1 A/g. The nanocomposites showed enhanced electrochemical behaviour of the nanocomposites when compared to pure GO. The nanocomposites also showed good cycling stability. The superior performance of the GO-CuO and GO-ZnO nanocomposite electrode renders it as a promising material for supercapacitors applications.

Applications of Ceramic/Graphene Composites and Hybrids

“…Both showed higher capacitance than the pure TMO compounds or their composites with CNTs, capacitance retention of more than 80% after 5000 cycles and high energy density (43.2 W·h·kg −1 ). Other electrodes with excellent capacitive performance were fabricated from CuO/GO and ZnO/GO composites, and tested with different electrolytes (KCl, Na 2 SO 4 and H 2 SO 4 ) [ 45 ], showing superior values for the tests with KCl at 1 A·g −1 (800 Fg −1 for CuO/GO electrode and 450 F·g −1 for ZnO/GO).…”

Recent advances in energy storage with graphene oxide for supercapacitor technology

“…17,147 These modications aim to optimize the balance between surface area, conductivity, and ion accessibility, resulting in improved energy storage capabilities. 148,149 The study conducted by Karbak et al 150 investigated the chemical synthesis of graphene oxide (GO) with a notable surface energy, aiming to evaluate its suitability for use in supercapacitors (SCs). Two distinct forms of graphene oxide (GO) were produced by the chemical exfoliation of graffiti materials with diverse tissue and structural characteristics.…”

Electrochemical performances and antibacterial activity of green synthesized cobalt oxide nanoparticles and poly (o‐Phenylenediamine) based textile supercapacitor

“…15,16 Nanocomposites have been widely investigated in this regard. [17][18][19][20] The present work focuses on the synthesis of PoPD using a green microwave-assisted technique. Cobalt oxide was also green synthesized using a drumstick pod extract and incorporated into the polymer matrix to prepare polymer nanocomposites.…”

“…Therefore, combining the properties of transition metal oxides and conducting polymers could be promoted as a productive method to obtain materials with enhanced application performances 15,16 . Nanocomposites have been widely investigated in this regard 17–20 …”