Synthesis and Characterization of Carbon Nano Sphere-doped Gd: Alpha Sb₂O₄ Nanostructure for High-Performance Energy Storage Applications

Background: To enhance the super capacitive properties of nanocomposites, the effective method is to combine carbon nanospheres with mesoporous structures with Gd3+:alpha-Sb2O4 inorganic nanocomposites (NC) to form hybrid electrodes. An as-prepared hybrid electrode material possesses increased energy density, high rate of reversibility and cyclic stability when incorporated in electrochemical cyclic voltammetric studies. Methods: In the present investigation, various wt % of C-nanospheres (C-x) (5%, 10% and 20%) were decorated over Gd3+: alpha-Sb2O4 nanocomposites and were synthesized by coprecipitation method. XRD, SEM, EDX, UV-visible, and XPS are only a few of the analytical techniques used to describe the as-prepared hybrid nanocomposites. Electrochemical cyclic voltammetry was carried out in a 6 M KOH solution, three-electrode system. Results: The crystal structure and morphology of C-x: Gd3+@ alpha-Sb2O4 NC showed a mixed hexagonal phase and agglomerated tiny irregularly shaped morphology that appeared as the C-x concentration increased. Redshift in optical absorption peak appeared (near UV-edge), and the optical band gap (E-g) value increased from 3.53 eV to 3.65 eV. The electrochemical supercapacitor showed the highest specific capacitance of 989 F/g at the current density of 1 A/g for C-20%:Gd3+@alpha-Sb2O4 NC compared with C-x:Gd3+@alpha-Sb2O4 (x = 5% and 10%) and undoped Gd3+:alpha-Sb2O4 NC. The change in phase angle and R-s value of 1.98 was attributed to the ideal supercapacitor properties. The cyclic stability after 5000 cycles with 79.71% capacitive retention was exhibited by C-20%:Gd3+@alpha-Sb2O4 NC. Conclusion: The present research introduces ease of synthesis of hybrid electrode materials possessing high active surface area, increased energy density, high cyclic stability, and reversibility in an aqueous solution.