Azo dyes represent a significant concern to the environmental regulations and proper wastewater treatment is crucial in mitigating its impact on ecosystems. This study investigates the removal of black azo dye from aqueous solution using silver oxide nanoparticles (Ag2O NPs) improved with green-like material. The trumpet vine leaf extracted was used as a capping and reducing agent to formulate the nanomaterial catalyst. A characteristics analysis using Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), Brunauer–Emmett–Teller (BET), Barrett–Joyner–Halenda (BJH), and Fourier-Transform Infrared Spectroscopy (FTIR) techniques was performed to examine the features of the catalyst. About 79% removal efficiency of azo black dye was reached using a 1.0 g/L dosage of the Ag2O nanoparticles under visible light exposure in batch mode reactor. The reusability analysis illustrates a stable behavior after five cycles of loading, and the kinetic study revealed that the reaction is compatible with the 1st order kinetic model. These findings suggest an effective, reliable, and bio-friendly photocatalytic candidate for a variety of water treatment applications.