Influence of Tungsten content on the Electrochemical Performance of CuWO₄ Nanoparticles for Supercapacitor Applications

The influence of composition on the physicochemical properties and electrochemical performance of CuWO4 nanoparticles with various tungsten contents synthesised by a sol-gel method was investigated for supercapacitor applications. X-ray diffraction confirmed the formation of crystalline CuWO4 while the characteristic Cu-O and W-O vibrations were observed by Raman spectroscopy. SEM-EDX analysis showed uniform morphology and suitable elemental composition. The electrochemical studies using cyclic voltammetry and galvanostatic charge discharge techniques revealed pseudocapacitive behaviour due to reversible Cu²⁺/Cu⁺ and W⁶⁺/W⁵⁺ redox reactions. The CuWO₄ (1:1) sample showed the highest specific capacitance of 204.5 F g⁻¹ at 0.25 A g⁻¹ due to its optimised Cu–O–W framework, higher electroactive surface area, and improved charge transport. These results highlight the critical role of tungsten content in tuning structure-property relationships and demonstrate the potential of CuWO₄ nanoparticles as efficient electrode materials for supercapacitor applications.