The hydrothermally synthesized CuWO₄ nanoparticles (NPs) were characterized with different analysis such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM), Energy Dispersive X-ray Spectroscopy (EDX), Cyclic Voltammetry (CV), UV-Visible and Photoluminescence (PL) analysis. The prepared CuWO₄ NPs were examined with Electrochemical Impedance Spectroscopy (EIS). SEM images show that CuWO₄ NPs are highly spherical shaped morphology and porous in nature. The optical band gap of prepared CuWO₄ NPs is found to be 2.12 eV. Photodegradation of diclofenac sodium (DFS) (medical waste) in the aqueous medium with CuWO₄ NPs under visible light irradiation shows 98% degradation. The CuWO₄ NPs was stable up to 5th cycle it can be used as a reusable photocatalyst for the DFS degradation. The electrical conductivity and dielectric properties of the CuWO₄ NPs at room temperature is analyzed by EIS studies. The bulk conductivity value of the prepared nanoparticles is 1.477×10-5 S/cm at room temperature. The conductivity of CuWO₄ NPs is found to be due to electrons movement. The CuWO₄ NPs shows higher photocatalytic and electrocatalytic activity for decomposition of DFS and methanol electro-oxidation in alkaline medium respectively.