We describe a green process for the generation of silver oxide (Ag₂O) nanoparticles from silver material through an electrochemical spark (discharge) process. The annealing operation was carried out on the produced nanoparticles to observe changes in the particle morphology and different properties. Ag₂O nanoparticles were characterized by x-ray diffraction analysis, Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, field emission scanning electron microscopy, energy-dispersive x-ray (EDX) spectroscopy and high-resolution transmission electron microscopy. With the rise in annealing temperature, the average crystal size of Ag₂O nanoparticles was increased proportionally and the shape was also changed. Plate-type structures were attained with high annealing temperatures. The EDX result confirmed the presence of silver and oxygen atoms. The band gap of the nanoparticle samples, which were produced by direct current and pulsating direct current, was noted to be 1.6 eV and 1.9 eV, respectively.