Interfacial coupling-induced electrochemical enhancement for excellent energy storage in Mo3Sn@WO3 heterostructures

The escalating worldwide energy crisis and the ecological consequences of fossil fuels have heightened the demand for high-performance energy storage systems, such as supercapacitors. In this study, a Mo3Sn@WO3 heterostructure was fabricated to enhance the electrochemical performance of WO3. Mo3Sn enhances electrical conductivity and provides synergistic redox-active sites, leading to improved charge transfer, structural, and electrochemical kinetics. XRD analysis confirmed the formation of a pure heterostructure with an average crystallite size of approximately 21.4 nm. Raman spectroscopy reveals strong interfacial bonding through W-O, Mo-O, and Mo-O-Sn vibrational modes. SEM images demonstrate that it has a porous and interlaced structure with high surface area, while EDX shows that the elements are distributed uniformly. CV curves show strong redox peaks indicating high pseudocapacitive behavior with high reversibility. GCD analysis delivers a specific capacitance of 309 Fg–1 at 0.8 Ag–1, with outstanding rate capacity. The heterostructure also demonstrated excellent cycling stability with 88.7% capacitance retention after 5000 charge–discharge cycles, confirming its outstanding long-term electrochemical durability. The EIS results show that the charge transfer resistance is minimal (0.92 Ω), so there is rapid electron and ion transport. The improved electrochemical performance is due to the synergistic interaction between Mo3Sn and WO3. This study illustrates that the rational engineering of Mo3Sn@WO3 heterostructures significantly improves interfacial charge transfer and ion diffusion, presenting a viable approach for the advancement of high-performance supercapacitor electrodes and energy storage applications.