Rational Design of W-Doped MoO ₃ Anchored on Carbon Nanospheres: A Diffusion-Controlled Pseudocapacitive Electrode for Next-Generation Energy Storage Applications

A shortage of high-efficiency energy storage materials characterizes the current fossil-fuel era. Researchers have found an effective solution to this issue in fabricating nanomaterials through deposition, etching, doping, and composite fabrication. These methods improve material performance by enhancing the synergistic effect. In this study, tungsten (W) doping effectively enhances the physicochemical properties of MoO 3, and carbon nanosphere decoration further improves electrochemical performance. Using XRD, XPS, SEM, and TEM characterization methods confirmed the successful formation of a well-integrated material structure. Electrochemical investigations via CV, GCD, and EIS demonstrate that engineering the material to achieve structural tuning creates a synergistic effect on storage performance. Taken together, this composite exhibits pseudocapacitor behavior, yielding a specific capacitance ( C s ) of 883.9 F/g at 10 mV/s. After 5000 charge–discharge cycles, the Coulombic efficiency is 94.8%, while the capacitance retention is 62.3%. The synergistic interaction of W-doped MoO 3 with CNS delivers enhanced electrochemical stability and high capacitive performance, highlighting its strong potential as an efficient electrode material for next-generation supercapacitors.