High performance supercapacitors based on samarium molybdate/nitrogen and phosphorous co-doped reduced graphene oxide electrodes

Nanocomposites produced with samarium(III) molybdate/N, P co-doped reduced graphene oxide (Sm₂MoO₆/NPRGO) combination may be very useful in the field of supercapacitors due to the active interaction between these two components. In this study, we used the sonochemical method, which is quite simple and cheap, to produce Sm₂MoO₆/NPRGO nanocomposite, which draws attention with its high-quality electrochemical performance. Surface and structural properties of Sm₂MoO₆ nanoparticles, NPRGO and Sm₂MoO₆/NPRGO nanocomposite structures were studied by X-ray photoemission spectroscopy (XPS), nitrogen adsorption/desorption studies, scanning electron microscopy, and X-ray diffraction analysis. The symmetric supercapacitive performance of the Sm₂MoO₆/NPRGO electrode exhibits a specific capacitance of 689 F g⁻¹ (at 2 mV s⁻¹) and could maintain 99.9% capacity after 4000 charge–discharge cycles. Additionally, the symmetric supercapacitors based on nanocomposite electrode demonstrate a high energy density (23.2 W h kg⁻¹ at 250 W kg⁻¹), outstanding power density (8000 W kg⁻¹ at 14.4 W h kg⁻¹). Generally, this nanocomposite was synthesized for the first time and its supercapacitive properties were investigated. The nanocomposite electrode exhibited good supercapacitor response, remarkable rate performance and excellent cycling stability in both 0.5 M Na₂SO₄ electrolyte.