Engineering Fe₂WO₆-based heterostructures for high-performance supercapacitors: the role of V₂O₅ and g-C₃N₄...

The development of advanced electrode materials is essential for improving the performance of next-generation supercapacitors. In this study, Fe₂WO₆ nanoparticles were synthesized via a hydrothermal method, followed by the fabrication of Fe₂WO₆@V₂O₅ and Fe₂WO₆@g-C₃N₄ heterostructures through an in situ deposition approach. XRD and FTIR analyses confirmed the successful formation of crystalline heterostructures with strong interfacial interactions, while SEM revealed porous and interconnected morphologies favorable for electrolyte penetration and charge transport. BET analysis demonstrated that Fe₂WO₆@V₂O₅ possesses a higher specific surface area (38.7 m² g^-1) and a larger pore diameter (13.6 nm) than Fe₂WO₆@g-C₃N₄, providing abundant electroactive sites and enhanced ion accessibility. UV-Vis spectroscopy revealed reduced bandgap energies of 2.71 eV for Fe₂WO₆@g-C₃N₄ and 2.59 eV for Fe₂WO₆@V₂O₅, indicating improved electronic conductivity. Electrochemical performance suggested that the Fe₂WO₆@V₂O₅ electrode delivered the highest specific capacitance of 355.3 F g^-1 at 0.8 A g^-1, low charge-transfer resistance (2.67 Ω), and excellent cycling stability (87.4%). These findings demonstrate that interfacial engineering of Fe₂WO₆ with V₂O₅ effectively enhances charge storage kinetics, making Fe₂WO₆@V₂O₅ a promising electrode material for high-performance supercapacitors.