Construction of ternary structured Dy2O3 nanorods/carbon spheres/few layered Dy2WO6 nanohybrids for electrochemical supercapacitors

Abstract

In this work, Dy₂O₃ rods and layered Dy₂WO₆ heterostructure were effectively interconnected by carbon spheres named Dy₂O₃/Dy₂WO₆/C-sph nanocomposite with a confined interface and it was fabricated using a simple solvothermal approach. These ternary nanocomposites were investigated by X-ray diffraction (XRD), UV–visible diffuse-reflectance spectroscopy (UV-DRS), Fourier transform-infrared spectroscopy (FT-IR), Raman, field emission scanning electron microscopy (FESEM) with energy disperse spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS) analyses systematically. The XRD data expose that the synthesized materials are formed with a virtuous crystalline state. The charge storage properties and electrochemical performances of the as-synthesized nanocomposites and pure components were assessed with the help of cyclic voltammogram (CV), galvanostatic charge–discharge studies (GCD), and electrochemical impedance studies (EIS), respectively. The rare-earth-based novel Dy₂O₃/Dy₂WO₆/C-sph nanocomposite as working electrodes established commendable electrochemical performances with a maximum specific capacitance value of 123 F/g at a current density of 0.4 A/g in 2.0 mol/L aqueous KOH solution. According to the stability measurements, it was observed that the initial capacitance was maintained at ∼93% even after 2500 cycles, indicating that good electrochemical stability with the lowest internal resistance values was obtained from EIS analysis. The electrochemical measurements suggest that the Dy₂O₃/Dy₂WO₆/C-sph nanocomposite enables great competence and can be used as alternative electrode material in supercapacitor devices to avail high energy efficiency in a sustainable approach.