In this study, cobalt oxide (Co3O4) nanoparticles (NPs) were constructed by using a sol-gel method. Cobalt nitrate hexahydrate served as the cobalt precursor, while fresh egg white proteins acted as both reducing and stabilizing agents. Several characterization techniques were employed for characterization, including SEM, energy-dispersive X-ray (EDX) analysis, UV-Vis spectroscopy, and X-ray diffraction (XRD). The SEM images showed that the nanoparticles exhibited a spherical shape and were agglomerated into larger structures. The XRD patterns displayed sharp peaks, confirming that the Co3O4 NPs have a crystalline structure. EDX analysis indicated the weight percentages of cobalt and oxygen to be 28.07% and 70.22%, respectively, which aligns with the expected composition of Co3O4. Furthermore, UV-Vis spectroscopy revealed an absorption peak at 340 nm, with a broader absorption range extending from 330 to 500 nm in the visible spectrum, suggesting potential applications in photocatalysis and sensor technologies. Finally, the Co3O4-NPs were assessed for photocatalytic potential by degradation of ciprofloxacin and methylene blue (MB) dye using UV light irradiation. Five different concentrations (0.015, 0.025, 0.035, 0.045, and 0.055 g) of dye and drug. The calculated maximum degradation efficiency for MB was 92.33, and for ciprofloxacin, it was found to be 76.23%. This research demonstrates the successful use of egg white proteins for the synthesis of Co3O4 nanoparticles, highlighting their promising characteristics for various applications like environmental pollutants degradation.