MoS2/Yb, Er-doped CeO2 composite synthesized by hydrothermal method for high-performance supercapacitor applications

Supercapacitors, also known as electrochemical capacitors, are advanced energy storage devices characterized by rapid charge–discharge cycles, high power density, and extended cycle life, achieved through the electrostatic storage of energy at the electrode–electrolyte interface. To enhance the performance of supercapacitors, developing composites with superior electrochemical properties is essential. In this study, molybdenum disulfide (MoS2) and MoS2/Yb, Er-doped CeO2 composites were successfully synthesized using a hydrothermal method. Powder XRD confirms the composite of CeO2 is present in a cubic phase, while MoS2 is in a hexagonal phase, with peaks corresponding to both materials being observed. The XPS analysis confirms the presence of Mo, S, Ce, O, Er, and Yb elements were observed. Morphological images portray the existence of MoS2 nanoflakes and growth of CYE as nanospheres on the nanoflakes of MoS2. The absorption analysis of the MoS2 and MCYE nanocomposite reveals that MCYE displays high absorption below 400 nm, with a distinct absorption band at 354 nm corresponding to the fluorite structure of CeO. The novelty aspect of this article is that electrochemical performance of MoS2/Yb, Er-doped CeO2 as an electrode material for supercapacitors is reported for the first time, to the best of our knowledge. The incorporation of ytterbium (Yb) and erbium (Er) co-doped cerium oxide (CeO2) with a highly conductive MoS2 support template led to the development of an asymmetric supercapacitor exhibiting enhanced capacitance, achieving 660 F/g at a current density of 1 A/g and 282 F/g at 10 A/g, with a 92.8% retention rate after 6000 cycles. Electrochemical studies demonstrated improvements in Coulombic efficiency, power density, and energy density, attributed to the synergistic effects and interfaces between the materials. These findings highlight the potential of MoS2/Yb, Er-doped CeO2 composites as promising electrode materials for advanced energy storage applications.