Hydrothermal Formulation of Dy2MoO6@rGO Nanostructure for Supercapacitors

Abstract

The exceptional intrinsic conductivity and structural stability of mixed transition metal oxides (MTMOs) make them a significant pseudocapacitive electrode for supercapacitors. However, a major challenge is their inappropriate structures facilitating extended cycling life and rapid Faradic redox reactions. The present research reports the hydrothermal combination of dysprosium molybdate (Dy2MoO6) with reduced graphene oxide (rGO) to advance the specific capacitance (Cs) and rate performance of supercapacitors. While comparing pure Dy2MoO6, the Dy2MoO6@rGO nanocomposite exhibits a higher Cs of 1118Fg−1 at a current density (j) of 1Ag−1 and retention capacitance of 83.7% after 10,000 successive cycles. The enhanced electrochemical performance of Dy2MoO6@rGO results from its advantageous features, such as high structural stability, greater reactive surface area, favorable ion adoption, and rapid ion/electron transfer rate during the redox phenomenon. Furthermore, the asymmetric supercapacitors (ASCs) employing Dy2MoO6@rGO as the positive and activated carbon (AC) as the negative electrodes presented a Cs of 282Fg−1 at a rate of 1Ag−1. When operated at 1.6V, the constructed Dy2MoO6@rGO//AC ASC achieves an outstanding energy density (Ed) of 19.2Whkg−1 and a power density (Pd) of 272.2Wkg−1. These outstanding findings suggest that the created nanostructures Dy2MoO6@rGO can be used in ultra-performance ASC devices. Moreover, the method simplifies developing efficient energy storage devices using MTMOs by enhancing capacitance and expanding the potential range in an alkaline electrolyte.