Bismuth oxide is the substance used in photocatalytic processes the most due to its excellent band structure and stability. It functions as the photo catalyst to degrade organic dyes like methyl orange and has a number of advantages as a catalyst. Purified BiO significant limitations that reduce its photocatalytic effectiveness, however. Dopant addition will thus improve its photocatalytic efficiency. Nitric acid, sodium hydroxide, cobalt nitrate, and bismuth nitrate are used to produce cobalt doped bismuth oxide nanoparticles. In order to create the necessary solution, sodium hydroxide was gradually added to a solution containing the nitrate of bismuth and cobalt nitrate till the pH value reached 4, which is the point at which the most precipitate is likely to form. After that, the mixture was put into a Teflon autoclave at 150°C for hydrothermal synthesis. The solution is then dried at 80°C after being rinsed with deionized water. The leftover material was then pulverized and calcined at 450°C in a muffle oven. The resulting particles were characterized utilizing a variety of methods, such as Uv-visible spectroscopy, FT-IR spectroscopy, XRD, EDX along with SEM. Using an UV-Vis, the absorbance of 2, 3 and 4 percent Co/BiO NPs with various Co concentrations be determined at the range of 292 nm, 303 nm and 310 nm each. The functional groups of cobalt-doped bismuth oxide nanoparticles were studied using FT-IR spectroscopy. The Co/BiO bond generated a signal in 883 cm^-1, whereas the maximum range of BiO stretch was 454 cm^-1. SEM Images of Co/BiO NPs be later put through to detailed investigation using a scanning electron microscope (SEM) at different magnifications. In the presence of cobalt, it was revealed that the diameters of Co/BiO NPs were 44.44 nm, 49.53 nm, & 50.41 nm at concentrations of 2%, 3%, & 4% respectively. This was accomplished with the use of Sherrer's equation, which also helped to establish the average crystalline structure of cobalt doped BiO. The activity of the produced NPs was examined for MO degradation under sun illumination. The 3Co/BiO photo-catalyst degraded more than 94% of the MO dye, whereas the 2Co/BiO nanoparticles and the 4Co/BiO nanoparticles each degraded roughly 93.04% and 92.72% of the MO dye, respectively, according to the findings of the photocatalytic activity.

Keywords; Hydrothermal Synthesis, Cobalt doped Bismuth Oxide, Nanoparticles, Photocatalysts, Characterizations, MO Dye Degradation,