Synthesis and Characterization of rGO doped RuO2 nanocomposites for Photocatalytic and Antioxidant Properties

Abstract

Recently, electrochemical energy storage has arisen to be one of the major areas of research to deal with the exorbitant energy demands of the modern civilization. Hasty modernization has amplified the demand for sustainable energy, and fuel cells have received much devotion for power generation based on renewable energy. Fuel cells have the competence of green technology as the electric energy generation from chemicals produces no combustion [1]. Consequently, beside fuel cells and battery technology, fascinating and challenging results observed in the recent past, during materialization of supercapacitors have triggered sharp increase in research proclivity to re-enter this aspect of renewable and sustainable energy storage technology. The performances of Supercapacitors mainly reliant on electrode materials, nature of electrolyte used and the range of voltage window hired. The unusual properties of Carbon-based electrode materials, such as widespread surface area, electrical conductivity, and faster electron transmission kinetics with low production cost. But their specific capacitances are found to be too low for commercialization. Ruthenium dioxide (RuO₂) owing to its high theoretical specific capacitance value has been generally predictable as promising materials for supercapacitor devices but high production cost, agglomeration effects stand as high non-invasion fence for commercial practice. Accordingly, RuO₂ based nanocomposites have been widely studied to minimize the material cost, with real-time enhancement in the electrochemical performances [2-3]. In this paper, an effective synthesis of rGO-RuO₂ composite for electrochemical sensor studies has been reported. The modified Hummer's method was used to produce reduced graphene oxide (rGO). The ruthenium dioxide (RuO₂) was introduced to the rGO via the hydrothermal method to form the composite. X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to examine the sample. The CV measurements show a significant improvement in electrochemical reversibility, with the specific capacitances of rGO and rGO/RuO₂ being 45 and 110 Fg^-1, respectively. These results indicate that the capacitive behaviour and electron transfer of the rGO/RuO₂ nanocomposite was significantly higher than that of rGO. The charge-discharge curves show good symmetry and linear deviations with time change, indicating superior capacitance. This is primarily due to the electrode reversible reaction, and it has also been revealed as a type of super capacitor electrode material. The electrode materials obtained have the highest specific capacitance and excellent rate capability.