This study delves into the synthesis and characterization of two stable phases of bismuth tungstate, Bi2WO6 and Bi2W2O9, using the gel matrix method. The research focuses on their potential applications in asymmetric supercapacitor electrodes and photocatalytic dye degradation. Structural analysis through XRD and Raman spectroscopy confirms the formation of single-phase nanomaterials. Electrochemical studies reveal that Bi2W2O9 exhibits superior performance compared to Bi2WO6, with an impressive energy density of 20 Wh kg−1 at a power density of 750 W kg−1. The study also fabricates an asymmetric supercapacitor device using Bi2W2O9 as the positive electrode and activated carbon as the negative electrode, demonstrating excellent cycling durability. Additionally, photocatalytic studies show that Bi2W2O9 is more effective than Bi2WO6 in degrading methylene blue under visible light irradiation. The research concludes that Bi2W2O9 is a promising material for both advanced energy storage and efficient photocatalysis, offering a scalable route to the development of multifunctional bismuth tungstate-based nanomaterials.